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124 articles
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WHITE PAPER: Freezing Blood Samples for Deferred Immunophenotyping
This study used the TVTs and BCTs to compare the immunophenotype of fixed peripheral whole blood samples at time zero, and after freezing at -80°C for 7 days. The structural integrity of the frozen TVTs and BCTs were also examined. Optimisation of storage conditions was further investigated to improve immunophenotyping after freezing. TVTs showed the best cell percentage differences from the control with average lymphocyte cell recovery of 77% compared to 26% for the BCTs. All three BCTs cracked during the freezing process while all of the TVTs remained intact. Storage optimisation experiments showed tubes frozen at an angle and thawed at 37°C performed best overall. These results raise the possibility that whole blood samples for immunophenotyping may be stored at -80°C for extended periods beyond 7 days. Further studies will aim to demonstrate the upper limit of time the sample will remain stable and suitable for immunophenotyping. Experiments will also be conducted to examine the suitability for use in phosphoflow assays. -
WHITE PAPER: Evaluation of TransFix/EDTA CSF Sample Storage Tubes compared to alternative preservation methods
Many central nervous system (CNS) diseases such as inflammatory neurologic diseases, leukaemia, or autoimmune diseases, are associated with the presence of white blood cells in the cerebral spinal fluid (CSF). The detection of leukocyte subsets in CSF is of vital importance for the accurate diagnosis and treatment of such diseases. However, low cellularity and cell viability of leukocytes causes challenges when analysing CSF with flow cytometry, and it is recommended that native CSF samples are analysed within 1 hour of lumbar puncture (Kraan et. al. 2008, De Graaf et al. 2011, Korfel et al. 2016). This eliminates the possibility of multicentre studies and centralised diagnostics (Sedek et al. 2020) resulting in heterogeneity in interpretation of the results of clinical trials and difficulty in the homogenous management of affected patients (Del Principe et al. 2020). Various methods of preservation/stabilisation of CSF samples have been attempted but there is little data comparing their performances in preserving lymphoid and myeloid cells in CSF for flow cytometry assessment. In this study, mock CSF (MAS-CSF spiked with PBMCs) was stabilised with TransFix/EDTA, basal RPMI and complete RPMI, and compared to untreated mock CSF to determine the most optimal stabilisation method. Samples were tested by flow cytometry at different time points over 3 days. Data showed that the TransFix treated samples provided consistent cell recovery for at least 72 hours after collection. Conversely, untreated, basal RPMI and complete RPMI samples exhibited a dramatic reduction in cell events compared to TransFix at all time points, including 0 hours (75.5, 83.0 and 47.8% reduction, respectively) and 0.5 hours (56.1, 73.3 and 35.3% reduction, respectively). These data indicate that TransFix/ETDA CSF Sample Storage Tubes provide clear benefits over the use of untreated or RPMI stabilised samples and should be used for all CSF samples destined for flow cytometric analysis. -
VyCAP's Puncher Technology for Single Cell Identification, Isolation, and Analysis
This paper focuses on the validation of the Vycap method for isolation of individual CTC's. These were analyses downstream for DNA. The authors used TransFix blood collection tubes (CTC-TVTs) to allow VyCAP single CTC isolation for up to 48 h after blood draw and preserve cell morphology while the cells do still retain a certain flexibility that allows efficient separation of the excess leukocytes, while keeping the CTC in the pore at the bottom of the microwell. -
Vaccination Against Histomonosis Limits Pronounced Changes of B-cells and T-cell Subsets in Turkeys and Chickens
The protozoan parasite histomonas is causative agent of histomonosis in Turkeys and chickens and causes a high mortality rate in Turkeys. Experimental vaccination has shown to protect these species. TransFix was used to stabilise 0.75ml and 1ml whole blood samples in order to analyse monocytes/macrophages and heterophils via Flow cytometry. -
Use of TransFix cerebrospinal fluid storage tubes prevents cellular loss and enhances flow cytometric detection of malignant hematological cells after 18 hours of storage
In patients with suspected or proven leptomeningeal localised haematological malignancies (LHM) in CSF, rapid assessment is required as cell numbers decline quickly after lumbar puncture. The study aim was to examine leukocyte numbers and detection of LHM by flow cytometry in 99 CSF samples from patients with suspected or proven LHM after 30 minutes and 18 hours of storage in i) TransFix/EDTA CSF Sample Storage Tubes ii) serum-containing medium and iii) no stabilising agent (untreated). It was found that leukocyte numbers in TransFix stabilised CSF were higher than in the corresponding untreated samples at both time points. After 18 hours of storage at 4 degrees Celsius, the detection of LHM was enhanced in TransFix stabilised CSF. For all discordant paired observations, the level of suspicion of a patient having LHM was higher for the TransFix stabilised samples than for the untreated samples. The authors concluded that the use of TransFix/EDTA CSF Sample Storage Tubes prevents cellular loss and enhances flow cytometric detection of LHM after 18 hours of storage. -
TransFix: A clinical sample stabilising fluid for use in clinical haematology and immunology
Transportation of clinical samples between clinical sites raises concerns about sample integrity. TransFix was developed as a stabilising solution with minimal dilution effect and which retains sample integrity for up to 10 days. This facilitates the flow cytometer and haematological analysis on normal, Leukaemia and HIV patients. Phase 1 studies examined 40 patients specimens and found no loss of antigenicity over a 10 day period for the following antigens: CD2, CD3, CD4, CD5, CD7, CD10, CD11b, CD13, CD14, CD19, CD20, CD22, Cd23, CD33, Cd34, CD45, CD79b, HLA-Dr and surface bound immunoglobulin. A full haematological profile (including differential) was obtainable at day 7. -
TransFix for delayed flow cytometry of endothelial progenitor cells and angiogenic T cells
Endothelial progenitor cells (EPC) and angiogenic T cells have not been validated for use in studies that involve delayed sample processing and analysis. Here, we report our results for the flow cytometric enumeration of circulating EPC and angiogenic T cells using TransFix-treated whole blood obtained from adult patients with cardiovascular disease and healthy volunteers. Both cell types promote neovascularization and vascular homeostasis. As such they have been put forward as novel diagnostic markers for endothelial dysfunction and may add prognostic information in patients with cardiovascular disease. Our findings indicate that by the addition of TransFix cellular antigen stabilizing reagent to whole blood, analyses can be postponed up to 7 days after blood collection. Therefore, this procedure may facilitate laboratory workflow, as well as the organization of multicenter studies, which requires analyses to be conducted in a central core laboratory. -
The utilisation of modern transport and telecommunications platforms to assist in the remote provision of paediatric cancer diagnostics in Tanzania
Conference Abstract: Interim diagnostic services were provided by OLCHC in Dublin for paediatric cancer screening in Tanzania utilising DHL to transport fixed bone marrow samples and communicating the results via the WhatsApp communication platform in an average of 2.9 days. The bone marrow samples were fixed with TransFix to maintain integrity during transportation. -
The role of tissue factor in activation coagulation system at pregnancy complications
The authors of this poster abstract propose a model to monitor activation of the coagulation system in preeclampsia and other pregnancy complications with Tissue Factor (TF) expression on monocytes by flow cytometry, and simultaneously fixing the TF-induced thrombin generation in plasma. To determine expression of tissue factor (CD142) on monocytes, the authors used multicolour flow cytometry (CD45, CD14, CD16b, and CD142), and used TransFix to stabilise samples that could not be analysed within 2 hours. -
The kinetics of γ-H2AX during radiotherapy of head and neck cancer potentially allow for prediction of severe mucositis
The Authors evaluated the changes in γ-H2AX phosphorylation in peripheral blood lymphocytes (PBL) as a potential biomarker to the severity of radiation-induced mucositis. Blood samples were stabilized by Transfix and H2AX phosphorylation levels were examined by flow cytometry using the Apoptosis, DNA Damage, and Cell Proliferation Kit (BD, USA). Cells were permeabilize using BD Cytofix/Cytoperm Fixation/Permeabilization Solution. -
The influence of fixation of biological samples on cell count and marker expression stability in flow cytometric analyses
In this review, the authors summarise the literature data on the influence of sample storage under different temperatures and times combined with different fixation conditions on the cell count and marker expression levels. Based on the findings of several extensive studies employing fixed PB samples, it can be concluded that the performance of particular fixative greatly depends on the analysed marker and specific PB cell population expressing a given antigen. Preservation of absolute cell count was usually better in Cyto-Chex®-fixed PB samples, whereas TransFix® tended to better stabilise marker expression levels. CSF-based studies reveal that both serum-containing media and TransFix® can prevent cellular loss and enhance FC-based detection of leptomeningeal localisations of haematological malignancies, the latter being more available and having longer shelf-life. As both cell count and marker expression level are the main determinants of quality of biological samples dedicated to FC analyses, it remains to be addressed by the investigators which is the fixative of choice for their specific research aims. -
The impact of stem cells on electron fluxes, proton translation, and ATP synthesis in kidney mitochondria after ischemia/reperfusion
This study aims to show the administration of bone marrow-derived stem cells (BMSCs) can aid recovery of mitochondrial respiration following ischemia/reperfusion (I/R) injuries. The BMSCs were used immediately following isolation from the extracted bone marrow and some were retained for characterisation. 3x106 of the BMSCs were resuspended in PBS and stabilised using 1 part TransFix to 5 parts cell suspension for subsequent immunophenotyping, allowing the researchers to complete other time sensitive aspects of the study. -
The Association of High Prevalence of Trophozoites in Peripheral Blood with Lower Antibody Response to P. falciparum Infected Erythrocytes among Asymptomatic Children in Sudan
The Authors of this paper examined the antibody reactivity of autologous plasma from symptomatic and asymptomatic malaria infected children against the infected erythrocytes' surface antigens using flow cytometry. The Authors use TransFix to stabilise variant surface antigens (VSA) for flow cytometric analysis. -
The Application of Nano-enrichment in CTC Detection and the Clinical Significance of CTCs in Non-Small Cell Lung Cancer (NSCLC) Treatment
Circulating tumour cells in non-small cell lung cancer patients lack tumour marker protein that systems such as CellSearch rely on. This paper therefore describes the application of nano-enrichment in CTC detection in non-small cell lung cancer, Cytell cell imaging, and EGFR and ALK mutation detection via ARMS-PCR and FISH. Blood samples were collected into CTC TransFix/EDTA vacuum blood collection tubes. -
TH17/Treg imbalance and IL-17A increase after severe aneurysmal subarachnoid hemorrhage
CSF and peripheral blood were analysed in patients after severe aneurysmal subarachnoid haemorrhage to assess TH17, TH1, TH2, T regulatory cells and neutrophils. These samples underwent flow cytometry and cytometric bead analysis. CSF was collected in TransFix tubes for flow cytometry for analysis. Flow Cytometry panel: BV450-conjugated anti-CD3, PerCPCy5.5-conjugated anti-CD4, APC-H7-conjugated anti-CD8, V500- conjugated anti-HLA-DR, FITC-conjugated anti-CD45, PE-conjugated anti-CD183 (CXCR3), PECy7-conjugated anti-CD196 (CCR6), APCconjugated anti-CD38, PE-conjugated anti-CD25, PECy7-conjugated anti-CD194 (CCR4) and APC-conjugated anti-CD127 (all reagents from BD Pharmingen, San Diego, USA) -
Ten-color 15-antibody flow cytometry panel for immunophenotyping of lymphocyte population
The Authors of this paper have developed a lymphoproliferative disorder screening tube (LPD- ST) with the aim to provide comprehensive immunophenotyping of lymphocyte subsets with minimal need for additional testing. The LPD- ST consists of CD4/kappa FITC, CD8/lambda PE, CD3/CD14ECD, CD38PC5.5, CD20/CD56PC7, CD10APC, CD19APC- A700, CD5APC- A750, CD57/CD23PB and CD45KO. They also claim that this new LPD- ST is more suitable with paucicellular samples such as cerebrospinal fluid (CSF) than previous lymphocyte subset panels. In their experiments, the Authors fix CSF samples in TransFix, and it is inferred that flow results match immunohistochemical staining results. -
Study of body fluid samples using flow cytometry: Six years of experience at the Hospital Universitario San Ignacio -Ponti cia Universidad Javeriana, Bogota - Colombia
The Authors discuss findings from 6 years of experience in implementing flow cytometry in Columbia. The authors used TransFix to stabilise all sample, consisting of mainly cerebrospinal fluid, but also bronchoalveolar lavage, pleural fluid, pericardial fluid and ascite fluid from patients with acute and chronic leukaemia, myelodysplastic syndromes, lymphomas, myeloma, autoimmune diseases, immunodeficiencies and solid tumours. The Authors final conclude that this work represents the first report at the national level supporting TransFix implementation in pre-analytical FCM studies of all body fluids that are processed in the clinical practice. -
Standardization of lymphocyte antibody binding capacity - a multi centre study
Quantitative flow cytometry is increasingly being used to characterise non-malignant and malignant disorders, inter and intra laboratory standardisation becomes an important issue. However the lack of standardisation methods and process controls with defined antibody binding values, limits direct comparison. The study showed that a standard protocol is required to achieve low CV's. Also that stable whole blood can be used as a process control with defined antibody binding capacity values. -
Standardization of Flow Cytometric Minimal Residual Disease Evaluation in Acute Lymphoblastic Leukemia: Multicentric Assessment Is Feasible
Flow cytometric (FCM) assessment of minimal residual disease (MRD) in acute lymphoblastic leukaemia (ALL) patients was assessed at 3 different sites in Italy and one in Germany to see whether standardization was possible.MRD-evaluation by FCM in ALL can be standardized for reliable multicentric assessment in large trials.In order to assess the inter-laboratory concordance, artificial samples were created using TransFix. TransFix was used to stabilise leukemic cells from nine patients (seven B cell ALL and two T cell ALL) and these cells were mixed into bone marrow preparations at different concentrations. These were then sent to the sites for FCM analysis. The concordance between all four centres was 98%. Therefore, TransFix was shown to be successful in stabilising leukemic cells. -
Stabilization of Transfected Cells Expressing Low-Incidence Blood Group Antigens: Novel Methods Facilitating Their Use as Reagent-Cells
This paper aimed to generate cell lines expressing blood group antigens (to represent low incidence blood group phenotypes) and to then stabilise these to facilitate their use as reagent cells in clinical laboratories. The addition of TransFix to the cells allowed cell stabilisation and antigen detection for at least 120 days and may facilitate the use of these cells in clinical laboratories, overcoming the limited availability of rare red blood cells. TransFix treated cells were test at 11 time points from Day 0 up to Day 120 showing better morphological preservation (FSC & SSC) vs fresh than lyophilised cells. -
Stability of canine and feline cerebrospinal fluid samples regarding total cell count and cell populations stored in "TransFix®/EDTA CSF sample storage tubes"
This research article looks into storing canine and feline cerebrospinal fluid samples in TransFix/EDTA CSF sample storage tubes. The determinant factors were total cell count and cell populations. TransFix was determined to be suitable for storing for extended periods of time before analysing lymphocytes and granulocytes by flow cytometry. The Authors observe leukocytes could not be adequately stained with turks solution and issues with CD14 monocyte detection. -
Stabilised cellular immuno-fluorescence assay: CD45 expression as a calibration standard for human leukocytes
Quantitative immunofluorescence of CD45 expression is important in a wide variety of clinical studies however prior to this study, ranges of antibody binding capacity (ABC) in both fresh samples and stabilised control material had not been defined. As part of their work to establish the ABC range for stabilised control materials, the authors used TransFix to stabilise human whole blood for assessment. These investigations confirmed that TransFix stabilised human whole blood samples retain a CD45 ABC/lymphocyte level at a comparable value to fresh samples for 10-14 days when assessed using the quantitative indirect immunofluorescence (QIFI) test. -
Role of flow cytometry immunophenotyping in the diagnosis of leptomeningeal carcinomatosis
Purpose: To explore the contribution of flow cytometry immunophenotyping (FCI) in detecting leptomeningeal disease in patients with solid tumors. CSF samples obtained from a lumbar puncture (n = 77) and from an Ommaya reservoir (n = 1) were collected in EDTA tubes containing 0.2 mL of an immunofixative reagent (TransFix, Cytomark), necessary to guarantee safe transportation. FCI seems to be a promising new tool for improving the diagnostic examination of patients with suspicion of LC. Detection of epithelial cells with a higher DNA content is highly specific of LC, but evaluation of the nonepithelial cell compartment of the CSF might also be useful for supporting this diagnosis. -
Research needs and challenges in the development of HIV diagnostic and treatment monitoring tests for use in resource-limited settings
The aim of this article is to review research priorities for current and new technologies to diagnose HIV and to monitor treatment response, including technologies to enumerate CD4 cell counts in resource-limited settings.
The Authors note that blood preservatives may allow for the preservation of whole blood so that the sample can be shipped to a centralized laboratory with up to 15 days (TransFix; UK NEQAS, Shefield, South Yorkshire, UK) from collection to testing. Blood preservatives may play a very important role in improving access to CD4 cell count testing as they will allow the sample to be transported to a laboratory where the testing will be performed. -
Relationships between emerging cardiovascular risk factors, z-BMI, waist circumference and body adiposity index (BAI) on adolescents
The body adiposity index (BAI) has been recently proposed as an alternative index to body mass index (BMI) and waist circumference (WC) to evaluate adiposity in adults. This study aimed to determine the correlation between BAI and emerging cardiovascular risk markers including circulating endothelial cells (CECs) in normal weight and obese adolescents. Percentage of CECs in peripheral blood were assessed by fow cytometric analysis: 400 uL cellular stabilization solution (TransFix) was added to a 4 ml of peripheral blood to preserve cell surface antigens. -
Reduction of intra and inter laboratory variation in CD34+ stem cell enumeration using stable test material, standard protocols and targeted training
The European Working Group on Clinical Cell Analysis has developed a single platform flow cytometric protocol for the enumeration of CD34+ stem cells. A standard protocol was used over 24 clinical sites together using a CD34+ stabilised whole blood control. The use of a common standardisation protocol and targeted training significantly reduced intra and inter laboratory CD34+ cell count variation. -
Recommendations for quality assurance in multiparametric flow cytometry: first consensus of the Brazilian Group of Flow Cytometry (GBCFLUX)
The Brazilian Group of Flow Cytometry have the objective of contributing to technical and scientific advances in Brazilian clinical and research laboratories. In this publication, they present consensus recommendations to ensure the process quality, technical standardization, and reproducibility of results for all FC working groups in Brazil. For quality control of the pre-analytical phase, they recommend to collect CSF directly into TransFix, which can then be stored at 2-8°C for 48-72 hours. -
Quantification of circulating CD34+/KDR+/CD45 dim endothelial progenitor cells: analytical considerations
A comprehensive review of characterisation of circulating endothelial progenitor cells with a particular focus on the considerations surrounding enumeration by flow cytometry and their impact on cardiovascular disease. The authors note TransFix can be used to prolong sample storage time for 7 days for this type of analysis. -
Quantification of Cells with Specific Phenotypes I: Determination of CD4+ Cell Count Per Microliter in Reconstituted Lyophilised Human PBMC Prelabeled with Anti-CD4 FITC Antibody
A surface-labelled lyophilised lymphocyte (Sll) preparation has been developed using human peripheral blood mononuclear cells prelabelled with a fluorescin isothiocyanate conjugated anti-CD4 monoclonal antibody. The sLL preparation is intended to be used as a reference material for CD4+ counting, including the development of higher order reference measurement procedures and has been evaluated in the pilot study CCQM-P102. The sLL reference material was prepared from a pool of three buffy coats from normal human donors, and the PBMCs were separated and labelled with anti-CD4 FITC monoclonal antibody, washed and resuspended in a fixative solution comprised of 10% TransFix. -
Quality assessment of CD34+ stem cell enumeration: experience of the United Kingdom National External Quality Assessment scheme (UK NEQAS) using a unique stable whole blood preparation
CD34+ peripheral blood stem cell mobilisation and harvesting has replaced autologous bone marrow as a source of stem cells for transplantation. Timing and adequacy of harvests rely upon the accurate enumeration of circulating CD34+ cells. Previous EQA schemes reported inter-laboratory CV's as high as 284%. A novel stabilised whole blood preparation was distributed to 91 laboratories in 21 countries and participants were required to determine the percentage and absolute values for CD34+ peripheral blood stem cells. Using this method inter-laboratory CV's were reduced as low as 22% for both percentage and absolute counts. -
Proficiency Testing to Assess Technical Performance for CTC-Processing and Detection Methods in CANCER-ID
The authors of this paper set out to determine the technical performance of technology used in circulating tumour cell processing and the detection methods in cancer-id. Both Siemens and Parsortix recommend TransFix CTC-TVT and TVT respectively for stabilisation when using their CTC technology. -
Platelet leukocyte aggregates and markers of platelet aggregation, immune activation and disease progression in HIV infected treatment naive asymptomatic individuals
The primary aim of this study was to determine the levels of platelet monocyte and platelet neutrophil interactions in HIV treatment naive individuals. This was achieved by measuring the levels of platelet monocyte and platelet neutrophil aggregates and assessing the association between platelet aggregates; markers of immune activation and disease progression. Measurement of Platelet CD62P (platelet activation marker), CD36 (platelet aggregation marker), PMAs (platelet monocyte aggregates, CD14+CD42b+), and PNAs (platelet neutrophil aggregates, CD16+CD42b+) was performed by flow cytometry. TransFix was added to whole blood samples at the time of red blood cell lysis to keep the consequential platelet activation to a minimum, limiting artefactual platelet activation induced by ADP which is released upon the lysis of red blood cells. -
Performance of aged, TransFix treated blood in the Guava EasyCD4 and EasyCD8 Assays
Monitoring CD4+ and CD8+ T cell counts has become essential in monitoring healthy individuals and patients infected with HIV / AIDS. The study reported the compatibility of 15 day old TransFix treated blood with the Guava EasyCD4 and EasyCD8 assays. The staining pattern for TransFixed samples over 15 days was almost identical to the staining pattern at day 0. At 30 days the staining pattern had started to show signs of deterioration but accurate counts could still be obtained. -
Optimization of a size-based enrichment method for improved circulating tumour cell detection in metastatic breast cancer patients
This thesis sets out to improve enrichment method to help better circulating tumour cell detection in metastatic breast cancer patients. Different blood collection tubes were tested along with fixation and permeabilization reagents. TransFix was determined as the most optimal when combined with the FIX&PERM cell fixation and the VYCAP size-based filtration system coupled with immunofluorescent staining. -
No Differences in Levels of Circulating Progenitor Endothelial Cells or Circulating Endothelial Cells Among Patients Treated With Ticagrelor Compared With Clopidogrel During Non-ST-Segment-Elevation Myocardial Infarction
The aim of this study was to determine differences in the number of endothelial progenitor cells and/or circulating endothelial cells found in peripheral blood in patients treated with either ticagrelor or clopidogrel during non ST-segment elevation myocardial infarction In this multicentre, randomized study (NCT02244710), all samples were kept in TransFix to enable adequate shipping to a central laboratory for analysis within 5 days Markers included: CD34, CD133, CD45, CD146, CD31, KDR (CD309), 7AAD, and Syto-16. Generic 7AAD and Syto-16 markers were used to define cell viability and nuclear cells, respectively. -
New trends in affordable CD4+ T-cell enumeration by flow cytometry in HIV/AIDS
Inexpensive Antiretroviral Therapy (ART) might soon be available to treat human immunodeficiency Virus (HIV) infections in resource-restricted areas of the globe. The number of CD4+ T-cells in the blood is the single most important laboratory parameter to select patients for therapy at the right time and to monitor the effect of ART. Stabilised blood cell standards and blood stabilising fluid, referred to as TransFix have recently been introduced for Quality Assurance. As the fast changing scenery of Flow Cytometry diminished the influence of company-orientated and instrument-orientated Quality Assurance Schemes, more emphasis had to be paid to the use of stabilised standard biological samples in international Quality Assurance Schemes. Preservative fluids, such as TransFix have been introduced with two beneficial effects. Firstly, TransFix added to whole blood at 1:10 dilution stabilises whole blood to perform reliable lymphocyte subset analysis for as long at 10 days. The catchment areas for laboratories can therefore be extended to receive samples from further afield. Secondly. TransFix has an additional bonus for quality assurance and interlaboratory technical standardisation. Samples shipped and tested within the time limits of 10 days between continents can be fully utilised to check the performance of instruments, reagents, full technologies and other parameters. -
New concepts in affordable cd4+ t cell enumeration for resource-poor settings
Flow cytometers can provide accurate CD4+ T cell counts for monitoring HIV disease but remain too expensive for resource-poor settings. In this research they combined six modern concepts (i-vi) in flow cytometry (FCM) for more efficient and economical CD4 T cell enumeration. Volumetric flow cytometers were used with (ii) CD4, CD8 and CD45 generic monoclonal antibodies (iii) using the panleucogating protocol (iv) on TransFix stabilized blood samples. A simple protocol using generic MAb's, and with no hidden costs such as microbeads, allowed the accurate reporting of 16 parameters including leukocyte absolute counts and differentials, CD4 and CD8 absolute and percentage values, total CD4+CD8 T cell counts as well as CD4/CD8 ratios. Correlations for absolute CD4 counts and percentage values were R2>0.96, with virtually no bias. The correlation for CD8 counts was R2=0.997, with a bias of 5.2% in favour of the CD3+,CD8+ test but with no significant influence on CD4/CD8 ratios. One single assistant processed 400 samples per day, which extrapolates to a throughput of 100,000 CD4 tests per year. -
Monitoring of human immunodeficiency virus infection in resource-constrained countries
The reference standards used to monitor human immunodeficiency virus (HIV) infection are flow cytometric analysis of T lymphocyte subsets to provide the CD4+ T cell count and molecular assays to quantify plasma HIV load. Few laboratories in resource-constrained countries can afford to perform these tests. This review discusses the above assays and their role in addition to clinical monitoring in resource-constrained countries. It states that TransFix TM stabilises whole blood for CD4 cell analysis for 7 days at 37 degrees Celsius and <3 days at 42 degrees Celsius. This stabilisation allows the transport of samples from distant sites to laboratories. -
Method Validation and Study of Immunophenotype NK and T lymphocytes by flow cytometry
The purpose of this study was to clarify the importance of the phenotypic markers of human NK and NKT cells in subjects with a significant increase of these cells. One of the aims was to study subjects with malignant populations (B-Chronic Lymphocytic Leukaemia, Acute Myeloblastic Leukaemia and Myelodysplastic Syndrome) in order to evaluate the suitability of a blood stabilizing reagent (TransFix®) in routine laboratory practice. The Author found that TransFix® stabilising reagent can be used reliably in flow cytometric analysis; light scatter characteristics and immunophenotype are well preserved in TransFix®-treated specimens stored at 4-10°C particularly concerning the blasts and lymphocytes populations for 15 days. -
Method validation and immunophenotypical study of NK and T lymphocytes by flow cytometry
The purpose of this study was the clarification of the importance of the phenotypic markers oh human NK and NKT cells definition in subjects with a significant increase of these cells percentage. Specimens with malignant populations (B-Chronic Lymphocytic Leukaemia, Acute Myeloblastic Leukaemia and Myelodysplastic Syndrome) were studied in order to evaluate the suitability of a blood stabilising reagent (TransFix) in routine laboratory practise. The study indicates that TransFix can be used reliably in flow cytometric analysis - light scatter characteristics and immunophenotype are well preserved in TransFix-treated specimens stored at 4-10 degrees Celsius, particularly concerning the blasts and lymphocyte populations for 15 days. -
Massive plasmablast response elicited in the acute phase of hantavirus pulmonary syndrome
The aim of this study was to determine the phenotype and frequency of blood B-cell subsets in ANDV+ patients from Argentina. The Authors demonstrate for the first time that a massive PB response takes place during a human primary infection with a member of the Bunyaviridae family, showing differential features with respect to plasmablast responses evoked after vaccination or other natural infections. The Authors found that TransFix-treated samples preserved the immunoreactivity of intracytoplasmic immunoglobulins in plasmablast, and went on to design and validated a leucocyte lysate antibodies assay for testing the antigen-specificity of antibodies present in the cytoplasmic fraction of white blood cell lysates. -
Low level leucocyte counting: a critical variable in the validation of leucodepleted blood transfusion components as highlighted by an external quality assurance study
Leucocyte counts of <5 x 106 per blood transfusion product are currently recommended in the UK in order to reduce transfusion related infections and febrile reactions. Routine leucocyte depletion requires the development of reliable internal and external quality assurance programmes. A stabilised low leucocyte blood control manufactured by UK NEQAS was used to determine inter and intra laboratory CV's. The study highlighted the variability in low level leucocyte counting, especially within the critical range of 5-30 cells/ul. The results highlighted the need for a standardised protocol and nuclear staining reagent for the routine validation of leucocyte depleted blood products. -
Longitudinal Follow Up of Immune Responses to SARS-CoV-2 in Health Care Workers in Sweden With Several Different Commercial IgG-Assays, Measurement of Neutralizing Antibodies and CD4+ T-Cell Responses
This study aimed to determine the previous infection of Health care workers in Sweden with Sars-Cov-19 and to compare this with the normal population. Different commercial IgG-assays were used along with measuring the neutralising antibodies and the CD4+ T-Cell responses. TransFix was used to fix the obtained samples which were stored until they underwent flow cytometry. Antibody panel: anti-CD3-V450 (#560365), anti-CD4-BV605 (#562658), anti-CD8-BV510 (#563919), anti-CD25-PE (#555432), anti-CD134-PECy7 (#563663), anti-CD69-FITC (#555530) and anti-CD137-APC (#550890) antibodies to the pre-fixed cells (all antibodies from BD Biosciences, Franklin Lake, NJ). -
Long-term effects of smallpox vaccination on expression of the HIV-1 co-receptor CCR5 in women
This study investigated whether smallpox vaccination is associated with a down-regulation of CCR5 on the surface of peripheral T-lymphocytes in healthy women in Guinea-Bissau. Cryopreservation of cells causes down-regulation of CCR5 on the cell surface. Antibody staining and analysis of surface CCR5 should therefore be performed on freshly isolated PBMCs. However, flow cytometry was not available in Guinea-Bissau during the study period. The Authors therefore validated the following method: Blood was sampled in special blood collection tubes containing TransFix (Data and description of TransFix validation is available from figshare https://doi.org/10.6084/m9.figshare.7139687.v1). -
Leukemic blasts are present at low levels in spinal fluid in one-third of childhood acute lymphoblastic leukemia cases
The authors assessed centralised flow cytometry of locally TransFix-fixed cerebrospinal fluid (CSF) samples versus local conventional cytospin-based cytology for detecting leukemic cells and evaluating kinetics of elimination of leukemic cells in CSF. CSF samples were collected into tubes containing TransFix to stabilise B-cell precursor ALL (CD3/CD10/CD19/CD20/CD34/CD38/CD45), and T-cell ALL (CD3/CD4/CD7/CD8/CD45/CD56), allowing samples to be shipped for centralised analysis, preferably within three days of lumbar puncture. To verify leukemic classification, the CSF from 2 patients were flow sorted followed by FISH targeting the leukemic karyotypes. The authors recommend the use of on-site fixation and rapid centralised flow cytometric analysis of CSF samples. -
Less expensive CD4+ T cell monitoring using panleucogating
Tests were carried out to compare the cost and accuracy of DP:lymphocyte gating using TriTEST with MultiSET software [LyG] and DP:panleucogating [PLG] and to evaluated TransFix to stabilize blood and extend the time between blood draw and testing.EDTA blood samples were analyzed within 24 hours by FACSCount, LyG and PLG. TransFix samples were evaluated after 3 and 7 days. Cells stabilized by TransFix, the correlation between results at day 3 and day 0 was excellent for PLG and FACSCount. Correlation between results at day 7 and day 0 were good only for PLG [R2=0.85]. In conclusion the PLG results correlated more closely than LyG with FACSCount results and TransFix allowed accurate testing for at least 3 days following blood draw. -
Interlaboratory variability of CD34+ stem cell enumeration. A pilot study to national external quality assessment within the Czech Republic
Quote: The study took place between November 2007 and May 2009 and consisted of three surveys. Ten laboratories took part in the study, but only nine laboratories participated in the first survey. Each laboratory was assigned a unique number (ULN) to retain confidentiality. Two samples of mobilized peripheral blood were included in every survey. Samples were stabilized with TransFix (Cytomark Ltd, Buckingham, UK),divided in 1 ml aliquots and shipped overnight by courier to the participants. The blood was collected from patients or healthy donors who underwent stem cell mobilization after giving informed consent. All subjects were negative for infectious diseases (humanimmunodeficiency virus, hepatitis B and C, syphilis).The stability of the samples was assured for at least 3 days (CV up to 5% in the stability study).Each laboratory performed the CD34+ enumeration according to its local protocol and practice and reported the measured values (leukocyte count,CD34+ percentage and absolute count) and some methodological details. All data were analyzed in the co-ordinating laboratory, and the results sent to the participants. The absolute CD34+ count was assignedas an indicator of laboratory performance. -
Interlaboratory Comparison of the TransFix®/EDTA Vacuum Blood Collection Tube with the 5 mL Cyto-Chex® BCT
An interlaboratory study was performed to compare the performance of the 3 mL TransFix®/EDTA Vacuum Blood Collection Tube (TVT), with the 5 mL Cyto-Chex® BCT tube (BCT). Both devices were tested for their intended use for collection and storage of whole blood specimens for immunophenotyping of leukocytes by flow cytometry for up to 14 days. Statistical concordance was demonstrated for both devices in relation to cell absolute count recovery. For cell marker signal, both devices exhibited a significant decrease in mean fluorescence intensity (MFI) for the detection of lymphocyte subsets and their target markers. There was a marked increase in autofluorescence observed for BCT stabilized lymphocytes whereas values for the TVTs were comparable to the control. There were eight instances of statistical equivalence between the level of antibody autofluorescence observed in the control tube and the TVT across both patient cohorts, versus two for the BCT. -
Infiltration of CNS by acute leukaemia: Analysis of fresh and TransFix stabilised CSF
A research study to determine whether acute leukaemia blasts present in CSF can be successfully stabilised by TransFix has concluded that TransFix preserved light scatter and key antigen expression patterns allowing analysis of diagnostic and follow up CSF specimens for patients with CNS infiltration. Full evaluation of the antibody panels to be used on transfixed samples is also required since some antigens are expressed dimly. -
Implementation of highly sophisticated flow cytometry assays in multicenter clinical studies: considerations and guidance
A discussion of the current challenges and solutions surrounding the design of multicentre studies involving flow cytometry analysis of biomarkers. Using TransFix/EDTA Vacuum Blood Collection tubes for sample collection is highlighted as a convenient approach for immunophenotyping assays. -
Immunophenotypic Characterization of Bone Marrow Mast Cells in Mastocytosis and Other Mast Cell Disorders
Mastocytosis is a term used to designate a heterogeneous group of disorders characterized by an abnormal proliferation and accumulation of mast cells (MCs) in one or multiple tissues including skin, bone marrow (BM), liver, spleen, and lymph nodes, among others. Recent advances in our understanding of mast cell biology and disease resulted in the identification of important differences in the expression of mast cell surface antigens between normal and neoplastic mast cells. Most notably, detection of aberrant expression of CD25 and CD2 on the surface of neoplastic mast cells but not on their normal counterparts lead to the inclusion of this immunophenotypic abnormality in the World Health Organization diagnostic criteria for systemic mastocytosis. Aberrant mast cell surface marker expression can be detected in the bone marrow aspirate by flow cytometry, even in patients lacking histopathologically detectable aggregates of mast cells in bone marrow biopsy sections. These aberrant immunophenotypic features are of great relevance for the assessment of tissue involvement in mastocytosis with consequences in the diagnosis, classification, and follow-up of the disease and in its differential diagnosis with other entities. In this chapter, we provide the reader with information for the objective and reproducible identification of pathologic MCs by using quantitative multiparametric flow cytometry, for their phenotypic characterization, and the criteria currently used for correct interpretation of the immunophenotypic results obtained. In cases in which it is not expected to perform sample processing within the first 24h following a bone marrow puncture, a stabilising solution such as TransFix should be used to avoid deterioration of cells. -
Identification of Neoplastic Infiltration of the Cerebrospinal Fluid (CSF) in Patients with Aggressive B-Cell Non-Hodgkin's Lymphoma (B-NHL) without Clinical Evidence of Leptomeningeal Disease: A Comparative Analysis of the Utility of Flow Cytometry (FCM) Versus Conventional Cytology (CC)
Quote: In all cases, the CSF samples were analysed simultaneously by CC at the institution of origin and FCM, centrally one institution. For the FCM analysis of the CSF, stabilised samples (TransFix, CYTOMARK) were systematically stained with the following combination of monoclonal antibodies: CD8-sIgl/CD56-sIgk/CD4-CD19/CD3/CD20/CD45 (FITC/PE/PERCPCY5.5/PECY7/APC/APCCY7). If the FCM test showed infiltration, an additional 6-color antibody panel was used for full phenotypic characterisation of the disease. -
Identification of Leptomeningeal Disease in Aggressive B-Cell Non-Hodgkin's Lymphoma: Improved Sensitivity of Flow Cytometry
We evaluate the sensitivity and specificity of a new 11-parameter Flow cytometry (FCM) approach versus conventional cytology (CC) for detecting neoplastic cells in stabilized CSF samples from newly diagnosed aggressive B-cell non-Hodgkin's lymphoma (B-NHL) at high risk of CNS relapse, using a prospective, multicentric study design. For multi-parameter FCM analyses, CSF samples (median volume, 2.0mL; range, 0.5 to 4.0 mL) were directly collected into tubes containing EDTA and 0.2 mL of TransFix (Cytomark) and shipped overnight to the central FCM laboratory. Immediately on arrival at the central laboratory, the volume of the CSF sample was measured (after subtracting 0.2 mL corresponding to the TransFix solution) and recorded; -
Human dorsal root ganglion pulsed radiofrequency treatment modulates cerebrospinal fluid lymphocytes and neuroinflammatory markers in chronic radicular pain
The paper investigates the effects of Pulsed radiofrequency on lymphocyte frequencies and secreted inflammatory markers in the cerebrospinal fluid (CSF) to identify clinical markers of chronic radicular pain. CSF was stored and stabilised in TransFix/EDTA CSF sample storage tubes for subsequent flow cytometry analysis (CD45-APC, CD3-APC-Vio770, CD4-VioBlue, CD8-PerCP, CD56-PEVio770) -
How to facilitate early diagnosis of CNS involvement in malignant lymphoma
The authors discuss several analysis methods to facilitate early diagnosis of CNS involvement in malignant lymphoma (CD19/10/45/kappa/lambda for B cell Lymphomas). They recommend stabilising CSF with TransFix if samples cannot be analysed within 1 hour for flow cytometric analysis. -
Higher rate of central nervous system involvement by flow cytometry than morphology in acute lymphoblastic leukemia
This paper investigates the use of flow cytometry (FCM) as apposed to traditional cytopathology methods for diagnosis of central nervous system (CNS) involvement in acute lymphoblastic leukaemia (ALL). In the discussion, the author discusses the limitations of FCM, such as the viability declines rapidly in cerebrospinal fluid (CSF) samples, and cell degeneration occurs within 1 hour of sample collection. As a solution, the author recommends the use of TransFix to stabilise CSF for up to 72 hrs. -
High-resolution imaging for the detection and characterisation of circulating tumour cells from patients with oesophageal, hepatocellular, thyroid and ovarian cancers
The purpose of this study was to develop and validate a novel, widely applicable method for detection and characterisation of circulating tumour cells from 4 tumour types. Blood samples were collected in TransFix collection tubes and stained for immunofluorescence by the following membrane antibodies and nuclear stains: EpCAM, cytokeratins 4, 5, 6, 8, 10, 13 and 18, survivin and CD45, and DAPI or DRAQ5. Circulating tumour cells were enriched using an EasySep human CD45 depletion kit, and were analysed using an ImageStream X Flow cytometer. -
Hexokinase 2 discerns a novel circulating tumor cell population associated with poor prognosis in lung cancer patients
This study aims to demonstrate Hexokinase-2 and its use in detecting novel circulating tumour cells. These CTCs are otherwise difficult to detect and have been linked with a bad prognosis in lung cancer patients. TransFix vaccum collection tubes were used to preserve blood cells which where then analysed using the HK2 marker -
Harvesting-induced stress in broilers: Comparison of a manual and a mechanical harvesting method under field conditions
The authors compare methods for harvesting Broilers (chickens) to improve animal welfare during harvesting. As a physiological parameter to measure stress, the authors measure the heterophil/lymphocyte ratio (H/L ratio) using rapid high-precision flow cytometry. Chicken blood samples were added to EDTA tubes, before being stabilized with TransFix reagent to allow transport to the testing facility. -
Guidelines on the use of multicolor flow cytometry in the diagnosis of haematological neoplasms
These guidelines have been developed by UK-based clinical flow cytometry (FC) experts along with clinical representatives to take into account advances in the state of the art of clinical flow cytometry since 2002. Their work was revised by the Haemato-oncology Task Force of the British Committee for Standards in Haematology (BCSH) before review by other UK-based Haematologists and FC experts, the BCSH and the British Society for Haematology committee. This document covers a varied range of topics, from selection and setup of flow cytometers through data analysis to training considerations for staff working in the clinical FC laboratory.The guidelines strongly recommend sample age and quality is assessed prior to analysis and in the case of cerebrospinal fluid (CSF), it is recommended that unless immediate analysis is possible then samples can be stored in TransFix/EDTA CSF Sample Storage Tubes for up to 72 hours before analysis*. *TransFix/EDTA CSF Sample Storage Tubes are currently a Research Use Only product and Cytomark recommends that internal validation of the product must be completed by the end user before considering use of the products in a clinical setting. -
Guidelines For Diagnosis, Prevention And Management Of Central Nervous System Involvement In Diffuse Large B-Cell Lymphoma Patients By The Spanish Lymphoma Group (GELTAMO)
This report by the Spanish Lymphoma Group (GELTAMO) aims to provide useful guidelines and recommendations for the prevention, diagnosis, and treatment of central nervous system diffuse large B-cell lymphoma patients with, or at risk of, leptomeningeal and/or brain parenchyma lymphoma relapse. The Authors summarise and recommend the use of standardised and validated >8-colour FCM evaluation of stabilised CSF in the diagnosis work-up of DLBCL patients at risk of CNS disease for the identification of occult CNSL, and state that immediate sample preservation (preferably in TransFix) is strongly recommended. -
Flow cytometry as a diagnostic tool in lymphomatous or leukemic meningitis
In patients with neoplastic meningitis (NM), early diagnosis is highly desirable because the rapid institution of intrathecal therapy may mitigate the course of the disease. Cytology, long considered the "gold standard" for diagnosis, has low sensitivity because of both the paucity of cells in the cerebrospinal fluid (CSF) and morphological similarities between benign and malignant cells. A comprehensive review of the literature from 2005 through 2011 was performed that focused on diagnostic modalities for lymphomatous meningitis. Several studies demonstrated the sensitivity of flow cytometry to be several-fold higher than that of cytology for the detection of CSF leukemia/lymphoma. Makes reference to use of TransFix to stabilise and transport CSF samples. -
Flow cytometric profiles, biomolecular and morphological aspects of transfixed leukocytes and red cells
Cytometric performance is suboptimal in aged unfixed specimens because of apoptosis that affects light scatter properties. Our findings highlight that lymphomonocytic cells are well stabilized even at suboptimal temperature and cell density. TransFix is able to abolish any apoptotic features and acts as an optimal blood preservative for appropriate preanalytical stabilization. -
Flow Cytometric Immunophenotyping of Cerebrospinal Fluid
Quote: Leptomeningeal disease is an important adverse complication occurring in patients with B and T cell lymphomas and acute leukemias of lymphoid and myeloid origin. Recent reports suggest that multiparameter flow cytometry immunophenotypic assessment of spinal fluid samples could improve the efficiency of detection of CNS involvement, due to its high specificity and greater sensitivity. However, spinal fluid samples are frequently paucicellular with a rapidly decreasing cell viability. Staining of spinal fluid therefore requires dedicated sample storage/transport, staining, and preparation protocols. The Basic Protocol in this unit outlines a consensus multiparameter (3- to 8-color) flow cytometry immunophenotypic protocol for the evaluation of CNS involvement of cerebrospinal fluid (CSF) samples by neoplastic cells. A Support Protocol describing the simultaneous assessment of surface and cytoplasmic antigens is also provided. Finally, in the Alternate Protocol, we describe a method to calculate absolute numbers of both normal and pathological cell subpopulations by adding counting beads to the assay. -
Flow cytometric detection of leukemic blasts in cerebrospinal fluid predicts risk of relapse in childhood acute lymphoblastic leukemia: a Nordic Society of Pediatric Hematology and Oncology study
The Authors investigated if flow cytometric analysis of cerebrospinal fluid (CSF) at diagnosis improves the prediction of relapse compared to traditional cytospin and microscopy methods in BCP-ALL and T-ALL cases. CSF samples were preserved on-site with TransFix allowing transport from 17 centres to a central laboratory for analysis. The Authors concluded that flow cytometric analysis of CSF improves detection of CNS leukaemia, distinguishes patients with high and low risk of relapse, and may improve future risk stratification and CNS-directed therapy. -
Flow cytometric CD34+ stem cell enumeration: Lessons from nine years' external quality assessment within the Benelux countries
Assessment of interlab variability with regard to Flow Cytometric CD34+ Stem Cell enumeration. Authors discuss the use of TransFix in an EQA scheme to improve interlaboratory variability. -
First-in-Human Study in Healthy Subjects with FR104, a Pegylated Monoclonal Antibody Fragment Antagonist of CD28
This paper documents a phase I clinical trial to test FR104 (an antibody which inhibits CD28) in humans as a potential treatment of transplant rejection and autoimmune diseases. Blood samples were collected in TransFix/EDTA Vacuum Blood Collection Tubes (TVTs) to monitor lymphocyte subsets (CD45, CD3, CD28, CD45RO, CD4, CD25, CD127. CD69, CCR7) at time points ranging from day 0 to day 113, from a cohort of 64 healthy subjects.
Phlebotomy time points were initially very frequent post drug administration (0.5, 0.75, 1, 2, 4, 8 and 24 hours). TVTs gave the benefit of providing accurate snapshots of the immune profile of the subjects within this condensed testing period whilst giving the technician the flexibility to test the blood in a more leisurely timescale. -
Evaluation of TransFix® mediated stabilisation of adipose-derived stromal vascular fraction for delayed flow cytometry analysis
In multi-centre studies where stromal vascular fraction (SVF) is used for immediate treatment, post-hoc assessment at a central or core facility of cell numbers, cell viability and immunophenotype may be necessary. Additional time taken to ship and store these samples can lead to time-dependant loss of cell markers and a reduction in cell viability. This paper provides an assessment of the suitability of TransFix for the purpose of SVF stabilisation across 77 consenting patients. The data shows that following treatment with TransFix the samples remain stable for up to seven days providing accurate total nucleated cell counts, stable populations of CD90, CD31 and CD45 markers and the potential to back calculate cell viability in the original sample. The authors also report an apparent increase in cell numbers post-stabilisation that is hypothesised to be due to a reduction in cell clumping as a result of treatment with TransFix. -
Evaluation of TransFix, a commercial whole blood stabilizing reagent. This product reduces HIV replication
Samples treated with TransFix retain morphology and cell surface expression over time. Shipping and handling of HIV+ samples involved inherent elevated costs and a risk of exposure to the HIV virus. The study showed that HIV+ blood samples showed a 1-log reduction in HIV replication as measured by HIV p24 antigen production. The results indicate that TransFix has the ability to cause significant reduction in HIV replication. -
Evaluation of stabilised blood cell products as candidate preparations for quality assessment programs for CD4 T-cell counting
Exceptionally robust cell preparations are needed for quality assessment programs. A suitable product must withstand the environmental stress related to transportation for a minimum of 6 day. Six preparations were evaluated by monitoring T-cell subset values for samples stored at 4 degrees Celsius, 22 degrees Celsius and 37 degrees Celsius. Sample stability was tested daily up to day 7. Only TransFix and ImmunoTrol were successful at stabilising blood samples across the full range of storage temperatures. -
Evaluation of sample quality as preanalytical error in flow cytometry analysis in childhood acute lymphoblastic leukemia
The Authors retrospectively assessed the rate of inadequate bone marrow and CSF samples as a source of preanalytical error in Acute lymphoblastic leukaemia (ALL). Cohort #3 of patients included 51 CSF samples: 22 native, and 29 collected in TransFix/EDTA CSF Sample Storage Tubes (TF-CSF-5-2). In Cohort #3, 9/22 native samples (41%) had inadequate cell viability (defined as <30% viable cells), compared to 5/29 (17%) of TransFix-treated samples. The authors also saw that PB contamination (“traumatic tap”, defined as >100 RBCs/ul) was reduced in TransFix treated samples, with 8/22 native samples (36%) showing contamination, compared to 5/29 (17%) of TransFix-treated samples. -
Evaluation of leukocyte stabilisation in TransFix treated blood samples by flow cytometry and transmission electron microscopy.
The study evaluated the effects of TransFix on leucocyte scatter characteristics, immunophenotyping, membrane permeability, absolute cell counting and morphology. The results showed that this short term stabilisation method is particularly suitable for the analysis of human lymphocytes. Good results were obtained with respect to antigen definition and absolute cell counting procedures -
Evaluation of a novel stable whole blood quality control material for lymphocyte subset analysis: Results from the UK NEQAS immune monitoring scheme
The suitability of a novel stable whole blood preparation for use as both daily and longitudinal quality control was demonstrated through the UK NEQAS Immune Monitoring scheme. The stabilisation procedure ensures retention of leucocyte light scatter and immunological staining characteristics for up to 300 days. The preparation is also fully compatible with flow cytometer technology, incorporating either whole blood lysis or no wash, no lyse techniques. The ranges of inter-laboratory CV's of the stabilised control were better than those previously obtained with fresh whole blood. -
Evaluating Effects of AIV Infection Status on Ducks Using a FlowCytometry-Based Differential Blood Count
This paper set out to try and determine the immune statutes of ducks. Avian influenza virus infection status of the ducks was evaluated using flow cytometry. The method used was looking into the differential blood count. TransFix was used to fix the blood samples as it can be difficult to analyse blood immediately under field conditions. -
EuroFlow antibody panels for standardized n-dimensional flow cytometric immunophenotyping of normal, reactive and malignant leukocytes
Section 3 discusses the design and evaluation of the 8-colour, 13 parameter Euroflow™ small sample tube (SST) and related sample preparation protocols aimed to evaluate CSF and Vitreous biopsy samples, in patients suspected of leukaemia. Samples collected either with culture medium with FBS of FCS, or in TransFix Sample Storage Tubes, which the author states in the general discussion result in optimal stabilization of the cells for a few days (for example, 48h) and improve cell detection. -
ESCCA/ISCCA protocol for the analysis of cerebrospinal fluidby multiparametric flow- cytometry in hematologicalmalignancies
This protocol by the ESCCA and ISCCA sets out the process for analysing cerebrospinal fluid via flowcytometry. It recommends that either the CSF sample should be processed within 60 minutes of harvesting or stored in TransFix tubes and confirms that it works for stabilising CSF cells. A lower peripheral blood contamination was also seen in samples that were fixed with TransFix. -
Enumeration of Rare Cells in Whole Blood by Signal Ion Emission Reactive Release Amplification with Same-Sample RNA Analysis
The Authors present a platform capable of detecting less than 30 cells from a whole blood sample collected in TransFix CTC-TVT tubes. Their technology is based on size-exclusion filtration, microfluidic sample handling, and mass spectrometric detection through signal ion emission reactive release amplification (SIERRA), and demonstrate compatibility with PCR-based gene assays. The authors show that the isolated, TransFix-treated cells, could then be used for downstream gene analysis provided a pre-treatment step was carried out. This resulted in a mRNA yield 100x greater than untreated TransFixed samples. TransFix allowed the authors to store samples between 24-120 h at room temperature before analysis. -
Enumeration of circulating fibrocytes for clinical use is asthma by oprimized single-platform flow cytometry assay
Elevated numbers of circulating fibrocytes is emerging as an easily accessible biomarker for asthma. In this report, blood samples were taken from 44 patients with asthma of various severity and 14 age-matched healthy individuals. Fibrocytes were quantified using flow cytometry. Blood samples were either processed within four hours or mixed with the cellular surface antigen-stabilizing agent TransFix and stored at 4 degrees Celsius for up to 96 hours before processing. Robust intra-assay variability demonstrated a good agreement between the fibrocyte counts measured in fresh whole blood and the fibrocyte counts obtained in stored whole blood at 48 and 96h. -
Enumeration of Antigen-Specific CD8+T Lymphocytes by Single-Platform, HLA Tetramer-Based Flow Cytometry: A European Multicentre Evaluation
European study to validate a method by Enumeration of Antigen-Specific CD8 T Lymphocytes by Single-Platform, HLA Tetramer-Based Flow Cytometry. The study was performed in 14 labs and 9 different European countries. All samples were collected in TransFix TVT's . Study found no difference between fresh samples and seven day old TransFix stabilised samples for binding of tetramer and CD57. -
Endothelial Progenitor Cell Response to Acute Multicomponent Exercise Sessions with Different Durations
Acute multicomponent exercises which lasted for various durations and the endothelial progenitor cell responses to these exercise sessions were measured. The study aimed to determine if the exercise sessions promoted the mobilisation of endothelial progenitor cells. Venous blood taken after exercise was treated with TransFix in an EDTA tube to stabilise the sample for flow cytometry analysis. Samples were stained with BV410 CD34 (BD Horizon), PE CD309 (VEGFR-2/KDR; BD Pharmingen), FITC CD144 (BD Pharmingen), BV510 CD45 (BD Horizon), and APC CD133/1 (Miltenyi Biotec) -
EMT-independent detection of circulating tumor cells in human blood samples and pre-clinical mouse models of metastasis
This paper explores detecting circulating tumour cells in human blood independent of epithelial-to-mesenchymal transition and pre clinical mouse models of metastasis. CTC analysis was carried out in three different ways, Cellsearch, parsortix and Vycap. TransFix was added to each spiked mouse blood sample for the Vycap assay and left at room temperature for 24-48 hours. -
Effects of resistance exercise on endothelial progenitor cell mobilization in women
This study aimed to determine the effect of a single bout of resistance exercise at different intensities on the mobilization of circulating endothelial progenitor cells (EPCs) over 24 hours in women. The Authors used TransFix to stabilise blood collected on EDTA until they could analyse by flow cytometry 3-4 days after collection (CD34, CD309, CD45). They also noted that it was possible to analyse TransFix stabilized blood cells (EPCs) up to seven days after blood collection. -
Effects of nano-TiO 2 aerosols showing two distinct agglomeration states on rat lungs
The study examined inflammation resulting from the inhalation of nono-Ti02 aerosols by rats. After exposure to inhalation the rats were anaesthetized with isoflurane and sacrificed by exsanguination. Fluids from the BAL (BALF) were collected with 0.9% saline. The lungs were washed with a total of 21ml of 0.9 % PBS in 5 steps. These samples were centrifuged to isolate the cells and the cells from the five washes combined. The cell pellet was re-suspended in 1ml of 0.9% PBS containing 1% BSA and 200ul of TransFix. TransFix stabilized cell fractions were examined using a range of techniques to determine the degree of inflammation resulting from inhalation of nano-Ti2 aerosols. The techniques used to examine the TransFix stabilized leucocytes included; total cell counts using a haemocytometer, differential cell counts for lymphocytes using the cytospin cell staining method and inflammation markers were quantified (IL-1 , IL-6, TNF-, MIP-1 and MCP-1) using the Bio-Plex Luminex assay. -
Effects of Cyclosporin A induced T-lymphocyte depletion on the course of avian Metapneumovirus (aMPV) infection in turkeys
The avian Metapneumovirus (Ampv) causes an economically important acute respiratoroy disease in turkeys. While antibodies were shown to be insufficient for protection against aMPV-infection, the role of T-lymphocytes in the control aMPV-infection is not clear. In this study, the role of T-lymphocytes in aMPV-pathogenesis in a T-Cell suppression model in turkeys was investigated. Blood samples were collected with a syringe and were immediately transferred to S-Monovette EDTA-tubes. A total volume of 400ul EDTA-treated blood was mixed with 80ul fixation reagent TransFix, resulting in a 1.2-FOLD dilution of the sample. Samples were then stored for up to 1 day until further analysis. -
Effects of benralizumab on airway eosinophils in asthmatic patients with sputum eosinophilia
The Authors evaluated the safety of benralizumab in adults with eosinophilic asthma and its effects on eosinophil counts in airway mucosal/submucosal biopsy specimens, sputum, bone marrow, and peripheral blood. One of the exploratory objectives in multicentre phase I study included evaluation of basophil in PB: Blood was collected in lithium-heparin and 0.4 mL of TransFix was added to stabilize and preserve cells for subsequent flow cytometric analysis. After shipping to a central testing facility (within 14 days) co-expression of IgE high-affinity receptor (FcεRI) and CCR3 with CD123 and chemoattractant receptor of type 2 helper T cells (CRTH2) were collectively consulted to identify the basophil population. -
Effect of broiler genetics, age, and gender on performance and blood chemistry
This study sets out to find how various factors such as age, genetics and gender influence the performance and blood chemistry of broilers. Rapid detection devices were used along with flow cytometry and post-mortem examination. EDTA blood was mixed with TransFix cellular fixative to preserve for shipping. -
Downregulation of the T-Cell Receptor by Human Immunodeficiency Virus Type 2 Nef Does Not Protect against Disease Progression
T-cell activation marker expression. Fresh whole blood was stabilized in a 5:1 ratio with TransFix (Cytomark) for 2 to 14 days and used for determination of T-cell surface activation marker expression using anti-HLA-DR-fluorescein isothiocyanate-, CD38-phycoerythrin (PE)-, CD4-peridinin chlorophyll protein-, and CD8-allophycocyanin-titrated monoclonal antibodies (BD Pharmingen). -
Double Blind, randomised, placebo-controlled intervention trial to evaluate the effects of Bifido longum CECT 7347 in children with newly diagnosed coeliac disease
The aim of this study was to conduct a 3-month double-blind, randomised, placebo-controlled intervention trial in children with newly diagnosed CD following a GFD in order to evaluate the effects of B. longum CECT 7347 administration on immune and anthropometric parameters, and on intestinal microbiota composition. For lymphocyte phenotyping, peripheral blood samples were collected in heparin tubes mixed with TransFix and sent immediately to IATA-CSIC at room temperature for cytometry analysis (CD45, CD3, HLA-DR,CD4, Foxp3, CD8) -
Direct Relationship between Virus Load and Systemic Immune Activation in HIV-2 Infection
This paper reports a study into the relationship between virus load and systemic immune activation in HIV 2 infection. TransFix was used to stabilise whole blood for 2-14 days and used for determination of T cell surface activation marker expression with anti-HLA-DR, CD38, CD4, and CD8. -
Differences in cerebrospinal fluid inflammatory cell reaction of patients with leptomeningeal involvement by Lymphoma and carcinoma
Dissemination of neoplastic cells into the cerebrospinal fluid (CSF) and leptomeninges is a devastating complication in patients with epithelial cell neoplasia and lymphomas. In this study, flow cytometry immunophenotyping was used to analyse CSF leukocyte populations in the CSF of patients diagnosed with leptomeningeal infiltration by solid tumors and lymphomas. CSF samples were collected in tubes containing ethylenediamine tetraacetic acid and an immunofixative reagent (TransFix) for safe transportation and were processed with a median of 3 days from extraction. -
Diagnostic and prognostic significance of flow cytometry immunophenotyping in patients with leptomeningeal carcinomatosis
A multi-center study with eight patient recruitment centers throughout Spain that used TransFix CSF tubes to stabilise CSF samples from 166 patients. The study examined the sensitivity and specificity of flow cytometry (FC) diagnosis for leptomeningeal carcinomatosis. Compared with Cytology, FC showed greater sensitivity and negative predictive value, but lower specificity and positive predictive value. The multivariate analysis revealed that the percentage of CSF EpCAM positive cells predicted an increased risk of death. -
Development of a method to measure acetylated histone H4 in the nuclei of circulating myeloid cells as a surrogate tissue for the pharmacodynamics of HDAC inhibitors in the treatment of solid tumors
This conference abstract details the development and validation of an assay to measure the proportion of myeloid cells in peripheral blood with nuclei localised acetylated Histone H4 detectable by immunofluorescence and imaging flow cytometry. Blood samples treated with the potential anti-cancer agent sodium valproate were then stabilised in TransFix, stained by anti-acH4 and DAPI then analsysed by an Imagestream MkII imaging flow cytometer. -
Detection of occult cerebrospinal fluid involvement during maintenance therapy identifies a group of children with acute lymphoblastic leukemia at high risk for relapse
To determine the clinical significance of the levels of lymphoblasts in the cerebrospinal fluid (CSF) of children diagnosed with acute lymphoblastic leukaemia (ALL).CSF samples from 136 patients were analysed by conventional cytology (CC) and flow cytometry (FCM) at the time of diagnosis and after intra-thecal therapy (IT). CSF samples for analysis by FCM were treated with TransFix at sample collection to facilitate transport of samples from 8 different hospitals to one centre for analysis. The results support previous findings that FCM analysis was more sensitive than CC in the detection of leukemic cells present in the CSF samples and can provide a powerful tool in detecting residual leukemic cells in the central nervous system. -
Detection of central nervous system involvement in childhood acute lymphoblastic leukemia by cytomorphology and flow cytometry of the cerebrospinal fluid
The authors retrospectively compared flow cytometric immunophenotyping (CFI) of CSF with cytomorphology (CM) at diagnosis or relapse of childhood acute lymphoblastic leukaemia (ALL). They concluded that FCI of CSF increased the detection rate of CNS involvement of ALL approximately two times compared to cytomorphology, and that patients with low level CNS involvement may benefit from additional intensified systemic or CNS-directed therapy. CSF specimens were processed immediately on receipt in the laboratory or fixed in TransFix and processed the next morning. The authors note that one of the main problems in analysing CSF is the rapid cell death of leukocytes after sampling. Therefore, the FCI and CM results also always reflect the time from sampling until the start of analysis. Routine use of stabilization media or fixative immediately after sampling could further facilitate detection of malignant cells. -
Detection of Central Nervous System Infiltration by Myeloid and Lymphoid Hematologic Neoplasms Using Flow Cytometry Analysis: Diagnostic Accuracy Study
The Authors evaluated the diagnostic performance of flow cytometry using a cell stabilizer (TransFix) for sample preservation compared to cytomorphology for the detection of CNS infiltration by lymphoid and hematologic neoplasms. To preserve and prolong cell viability, samples submitted for immunophenotyping were collected in Transfix/EDTA observing the ratio of 1:10 TransFix/CSF. Analysis was performed using the Euroflow Small Sample Tube. Patients with suspected infiltration by acute myeloid leukemia (AML), multiple myeloma, and acute B- and T-cell lymphoid leukemia were further investigated using an extended antibody panel. The authors comment that the use of Transfix allowed the receipt of samples from distant centres avoiding stability problems, and concluded that FCM analysis with TransFix improved accuracy compared to cytomorphology, particularly in low-volume and low-cellularity samples. -
Detection and Characterization of Circulating Tumor Associated Cells in Metastatic Breast Cancer
This paper describes the use of the Screencell method of size-exclusion isolation of CTCs, circulating tumour cell clusters (CTC clusters), CTCs of epithelial-mesenchymal transition (EMT) and cancer associated macrophage-like cells (CAMLs). Blood samples collected in TransFix tubes and analysed within 72 hours. Cytological Analysis was performed by immunofluorescence staining of cytokeratins (CK-8, 18 and 19), DAPI, CD45 for CTCs, and EMT-CTCs were stained for Vimentin and N-Cadherin. Cell sorting was performed by the DEPArray™ system. TP53 and ESR1 Mutations in CTCs were analysed by Sanger sequencing. -
Detection & outcome of occult Leptomeningeal disease in diffuse large B-cell lymphoma and Burkitt lymphoma
Cytology of cerebrospinal fluid (CSF), the diagnostic gold standard has a low sensitivity with reported false negative rate of 20-60% suggesting that pre-treatment involvement of leptomeningeal disease is greater than initially reported. CSF was either analysed within an hour of lumbar puncture, or it was stabilised by two methods, one of which was using TransFix using the method outlined in the paper. Results provided the first evidence that occult CSF involvement by DLBCL or BL is clinically meaningful and associated with an adverse outcome. Results also indicated that patients at risk of CNS disease will benefit from intrathecal chemotherapy. -
Cytopathological Heterogeneity of Circulating Tumor Cells in Non-metastatic Esophageal Adenocarcinoma
This study sets out to discover the cytomorphology of circulating tumour cells in non-metastatic esophageal adenocarcinoma and their heterogeneity. Size-based cell filtration was carried out to determine the size of the CTCs. TransFix CTC tubes were used for collection of blood specimens which were sent within 24hrs of collection to the CTC laboratory. CTC enrichment was performed by cell size-based filtration using the ScreenCell® Cyto kit (ScreenCell, Sarcelles, France). -
Current strategies in the diagnosis of diffuse large B-cell lymphoma of the central nervous system
A detailed review of current strategies used in the diagnosis of diffuse large B cell lymphoma. The use of flow cytometry to detect CSF involvement in Primary CNS Lymphoma (PCNSL )provides improved diagnostic sensitivity as compared to cytopathology alone. With the availability of TransFix it is now possible to preserve CSF for up to 10 days. Accordingly it is now possible to analyse CSF samples from PCNSL patients in a central laboratory, preferably within a large multi-centre study. -
Contribution of cerebrospinal fluid sCD19 levels to the detection of lymphoma and its impact on disease outcome
The Authors treat CSF samples with TransFix for Flow Cytometry analysis within 24 hours. Samples are stained using the EuroFlow small sample tube (SST: CD20, CD45, CD8-surface membrane immunoglobulin (SmIg)lambda, CD56-SmIgkappa, CD4, CD19, SmCD3-CD14, CD38) -
Combining MYD88 L265P mutation detection and clonality determination on CSF cellular and cell-free DNA improves diagnosis of primary CNS lymphoma
This paper aimed to improve the diagnosis of primary CNS lymphoma and make it less invasive, this was achieved by using both clonality detection on CSF cellular and cell-free DNA and mutation detection. TransFix cell stabilising agent was used in the CSF collection tube for the flow cytometry evaluation. CSF cells were labelled with an eight-colour FCM antibody panel including anti-CD45 (HV500, Becton Dickinson), CD3 (BV421, Becton Dickinson™), CD4 (PE-CY7, Becton Dickinson™), CD8 (APC-AF750, Beckman Coulter), CD5 (APC, Becton Dickinson™), CD19 (PC5.5, Beckman Coulter™), kappa (FITC, Agilent™) and lambda (PE, Agilent™) -
Collection, Storage, and Preparation of Human Blood Cells
Human peripheral blood is often studied by flow cytometry in both the research and clinical laboratories. The methods for collection, storage, and preparation of peripheral blood will vary depending on the cell lineage to be examined as well as the type of assay to be performed. This unit presents protocols for collection of blood, separation of leukocytes from whole blood by lysis of erythrocytes, isolating mononuclear cells by density gradient separation, and assorted non-flow sorting methods, such as magnetic bead separations, for enriching specific cell populations, including monocytes, T lymphocytes, B lymphocytes, neutrophils, and platelets, prior to flow cytometric analysis. In some instances, such as shipping specimens from a distant site, it may be necessary to store blood for brief periods of time prior to staining. Several commercially available reagents, such as TransFix can be used to treat blood for storage. As an example of using these, a protocol for using TransFix is provided in this publication. -
Clinical significance of occult cerebrospinal fluid involvement assessed by flow cytometry in non-Hodgkin's lymphoma patients at high risk of central nervous system
Quote: The specific techniques and procedures used for the analyses of CSF samples have been previously described in detail (21). CSF samples were analysed in parallel using CC in the hospital of origin and centrally by FCM at the Cytometry Service of the University of Salamanca (Spain) using a standardised 11-parameter FCM immunophenotypic assay of CSF samples stabilised with 0.2 mL of TransFix added at the hospital of origin. -
Clinical Samples: Selection, Shipping, and Processing
Flow Metric explores the various methods for selecting, shipping and processing samples. They mention various options for preservation-fixation solutions one of which being TransFix. -
Clinical relevance of flow cytometric immunophenotyping of the cerebrospinal fluid in patients with diffuse large B-cell lymphoma
Central nervous system (CNS) relapse is an uncommon but dramatic complication of diffuse large B-cell lymphoma (DLBCL). Several studies have demonstrated the superiority of cerebrospinal fluid (CSF) flow cytometry (FCM), as compared with conventional cytology (CC), in detecting occult leptomeningeal disease. The clinical relevance of a positive FCM still has to be clarified. Makes reference to use of TransFix to stabilise and transport CSF samples. -
Circulating Tumor Cells: a Real-Time Liquid Biopsy
Chapter 5 details EpCAM independent CTC isolation techniques. To investigate multipores microsieves, the author used CTC TransFix/EDTA Vacuum Blood Collection Tubes and the VyCap CTC platform. Results show that filtration of whole blood is possible using the VyCap 8 pore microwell chips. Isolated spiked cell lines were permiablised using Fix&PERM, then stained with anti-Pan Cytokeratin CK-11 and AE1/AE3, and anti-CD45 and CD16. Results showed clearly CD45 positive cells and spiked tumor cells. -
Circulating endothelial cells as biomarker for cardiovascular diseases
Validation of a new assay to evaluate CEC's and EPC's as a biomarker for cardiovascular diseases. All blood samples were collected into TransFix TVT's (3ml) and analysed by FACS. CEC's were defined as DNA+, CD45dim, CD31+, CD146+ and CD36+/- -
Characterisation of the effects of pulsed radio frequency treatment of the dorsal root ganglion on cerebrospinal fluid cellular and peptide constituents in patients with chronic radicular pain: A randomised, triple-blinded, controlled trial
In this tripled-blinded control trial, the authors aimed to characterise the CSF cellular and peptide constituents in patients with chronic neuropathic pain (CNP) and the effect of pulsed radiofrequency (PRF). As part of the trial, CSF samples were stabilised in Transfix/EDTA CSF sample storage tubes for subsequent analysis of by flow cytometry. Lymphocyte subsets were characterised by CD45, CD3, CD4, CD8, CD56, CD69, CD45RA, and CD27 markers. The authors conclude that PRF is superior to local anaesthetic administration for the management of radicular pain and is associated with CSF constituent modulation in vivo. Patients with CNP have lymphocyte characteristics which suggest immune activation. -
Cerebrospinal fluid findings in patients with hematologic neoplasms and meningeal infiltration
This study sets out to discover the relationship between CSF findings and infiltration of neoplasms into the CNS. Cytomorphology and Flow Cytometry were both used to assess their diagnostic capacities of this. TransFix was used in this study to help preserve cell stability for immunophenotyping whilst the samples were being transported for analysing. -
CD45 assisted panleucogating for accurate, cost effective dual platform CD4+ T cell enumeration
A higher accuracy and precision of CD4 counts was documented with Pan Leucogating compared with lymphocyte gating using stabilised blood controls provided by UK NEQAS. These results were verified with 183 fresh samples and 112 TransFixed samples. These observations showed that dual platform leucocyte counts should replace lymphocyte counts. -
CD4 Intragenic SNPs Associate With HIV-2 Plasma Viral Load and CD4 Count in a Community-Based Study From Guinea-Bissau, West Africa
A second, back-up method for lymphocyte subset measuring was also in place. For this method, 100 μl "TransFix" solution (Cytomark UK) 24 was added to 500 μl fresh blood and roller-mixed for 5 minutes, after which the sample was kept in a refrigerator at 4 degrees Celsius and transported to the MRC Laboratories in Fajara, The Gambia. When the routine method failed, the transfixed samples were stained with fluorochrome-conjugated monoclonal antibodies manually rather than by Q-Prep, and analyzed in the FACS calibur, using the MultiSet software (Becton Dickinson, Erembodegem, Belgium). Results were regarded as invalid if the CD3 % was < 45%, or if the sum of CD4 % and CD8 % was more than 10% different from the mean CD3 %. In order to investigate whether the results of the two methods (routine and back-up) were comparable, 13 samples were processed using both methods and results compared. The agreement was excellent (r2 = 0.89 for CD4 %). In addition, a Bland and Altman test 25 was performed to compare the two methods and indicated no difference between them (p = 0.3). -
CD26 Expression on T Helper Populations and sCD26 Serum Levels in Patients with Rheumatoid Arthritis
The Authors studied dipeptidyl peptidase IV (DPP-IV, CD26) expression in different T helper cells and serum soluble DPP-IV/sCD26 levels in rheumatoid arthritis (RA) patients, correlated these with disease activity score (DAS), and examined how they were affected by different therapies. The authors concluded that, according to their CD26 expression, different cell subsets could serve to monitor RA course, and an uncharacterized T helper CD26- subset, not targeted by therapies, should be monitored for early diagnosis. Blood cells were collected using TransFix Vacuum Blood Collection Tubes and stored at 4°C until use. -
Cancer-associated Macrophage-like Cells in Patients with Non-metastatic Adenocarcinoma of the Esophagus - Cytomorphological Heterogeneity
This paper demonstrates the presence and phenotype of cancer-associated macrophage-like cells (CAML) as a liquid biomarker in Esophageal adenocarcinoma (EAC) patients. Peripheral venous blood samples were taken before initiating any neoadjuvant treatment using Circulating Tumour Cell TransFix/ EDTA Vacuum Blood Collection Tubes, to facilitate shipping and storage for up to 5 days, before CAMLs were isolated using ScreenCell® Cyto-R devices (ScreenCell, Sarcelles, France), then stained with standard May-GrunwaldGiemsa-staining for cytological analysis. -
Analysis of Neural Progenitor Cells in The Cerebrospinal Fluid of Preterm Infants with Posthaemorrhage Ventricular Dilatation
The Author hypothesised that Neural Progenitor Cells (NPC) are present in the CSF of premature infants with posthaemorrhagic ventricular dilatation (PHVD). Their aim was to develop and optimize the methods and techniques to identify and characterize NPC in the CSF of preterm infants with PHVD. When the author could not access fresh CSF samples, they used TransFix to stabilise antigens for cell counting via FACS for up to 8 days. -
An examination of the neuroimmune interactions of amitriptyline, spinal cord stimulation and opioid therapy in human neuropathic pain
This thesis looks into neuroimmune interactions in human neuropathic pain. The interactions explored are of amitriptyline, spinal cord stimulation and opioid therapy. This was achieved by taking cerebrospinal fluid before and after treatment and screening for neuropathic pain. Flow cytometry was used to compare the baseline and post intervention samples. TransFix was used to fix the sample for storing before use of flow cytometry and in vortexing. Panel 1(T cells) contained: CD-8, CD4, CD27, CD45, CD69, CD-45RA (Mitlenyi Biotech, Germany) and CD3 PE-eFluor 610 (eBioscienceThermoFisher Scientific, USA). Panel 2 (NK cells) contained: CD56, CD69, CD45, and CD3-PE- eFluor 610 (Biosciences, Dublin, Ireland). -
An accurate and rapid single step protocol for enumeration of cytokine positive T lymphocytes
This paper sets out to determine the fastest and most accurate protocol for determining the number of cytokine positive T-lymphocytes. After the cells had been harvested and washed they were fixed overnight in TransFix then pooled in a PBS isolation buffer. -
Affordable CD4+ T cell counts by flow cytometry. II. The use of fixed whole blood in resource poor settings
The feasibility and precision of CD4 counting in resource poor areas was tested using TransFix. It has been shown that immunological gating, including the primary identification of T, B and NK cells by virtue of their specific antibody binding capacity, is a robust method for absolute cell counting. With TransFixed samples primary CD4+ gating can be performed with great precision. There was also no difference in the precision of CD4+ counts performed on fresh cells in Tanzania and TransFixed cells in South Africa. TransFixed samples from smaller clinics can be batched over a period of one week for shipment to local or regional hospitals for analysis. -
Advances in CD4 cell enumeration in resource-poor countries
The availability of antiretroviral medications increases the need for CD4 cell assays to monitor disease progression and the efficacy of therapy in resource-poor countries. Simplified flow cytometry is needed in centralized clinics, but there is a critical need for even less expensive easier methodology that can be used in smaller laboratories and in rural villages. TransFix can be used to stabilise samples for transportation to central laboratories. -
Absolute CD4+ T-lymphocyte and CD34+ stem cell counts by single platform flow cytometry: the way forward
Stabilised blood controls for CD34 and CD4 were distributed to 280 laboratories worldwide, every 2 months for a year for absolute cell counts. Results were correlated by UK NEQAS. The study showed that the single-platform approach produced consistently lower inter laboratory CV's for both CD4+ and CD34+ enumeration. Furthermore such technology is likely to prove the method of choice for the quality control of leucodepleted blood products. -
A rapid high-precision flow cytometry based technique for total white blood cell counting in chickens
TransFix (Cytomark) was used to stabilise samples to demonstrate that samples can be shipped and stored prior to analysis. TransFix was used to stabilise and transport the avian blood samples. The automated analysis of total white blood cell count and white blood cell differentials is routine in research and clinical diagnosis in mammalian species. In contrast, in avian haematology these parameters are still estimated by conventional microscopic procedures due to technical difficulties associated with the morphological peculiarities of avian erythrocytes and thrombocytes. Both cell types are nucleated and fairly resistant to cell lysis, a prerequisite for automated leukocyte quantification and differentiation by commercial instruments. By using an anti-CD45 monoclonal antibody in combination with selected subset specific markers we have established a simple (no-lyse no-wash single-step one-tube) flow cytometry based technique for high precision chicken blood cell quantification. -
A proficiency testing program for flow cytometry: Istanbul experience
TransFix was used to prepare External Quality Assurance samples for CD4 Immune Monitoring -
A Novel Strategy for Detection and Enumeration of Circulating Rare Cell Populations in Metastatic Cancer Patients Using Automated Microfluidic Filtration and Multiplex Immunoassay
In this study, the performance of a novel approach for detection and enumeration of multiple rare cell populations was evaluated in the blood of metastatic breast and lung cancer patients using an automated microfluidic filtration and multiplex immunoassay strategy. Different circulating rare cell populations were detected and enumerated, including circulating tumour cells (CTCs), circulating mesenchymal cells (CMCs), circulating endothelial cells (CECs), and putative circulating stem cells (CSCs). Simultaneous assessment of CTCs, CMCs, CSCs and CECs may provide new tools to study mechanisms of disease progression and treatment response/resistance. The highly controlled filtration process and the multi-step staining parameters were optimised to minimise the detection of false positives in healthy donor blood. Use of TransFix®, along with controlled shipping and storage conditions contributed to the high rate of reportable results (98%). Blood was collected into tubes containing K3EDTA and 0.45mL TransFix® in customised TransFix/EDTA Vacuum Blood Collection Tubes (CTC-TVT-09-50). -
A British Society for Haematology good practice paper: Recommendations for laboratory testing of UK patients with acute myeloid leukaemia
The British journal of haematology recommendations for lab testing of UK patients of acute myeloid leukaemia. TransFix is suggested as the option for extending the life of the sample. -
4EVER: Assessment of circulating tumor cells with a novel, filtration-based method, in a phase IIIb multicenter study for postmenopausal, HER2-negative, estrogen receptor-positive, advanced breast cancer patients
The presence of circulating tumor cells (CTC's) has been shown to be of diagnostic relevance for patients with early and advanced breast cancer (BC) The usefulness of CTC assessments depends upon accurate cell counts and the corresponding analysis of molecular targets. Patient blood samples were preserved using TransFix vacuum blood collection tubes and CTC's were detected by image analytics after fluorescence scanning microscopy. The clinical trial is ongoing.