TransFix®: A Cellular Antigen Stabilisation Reagent
TransFix® is a patented, CE marked cellular stabilisation solution that preserves cell surface antigens for a minimum of 10 days at 2-22°C and for 4 days at 37°C (1). TransFix is added to whole blood samples at the time of venepuncture, and provides stabilisation so that extended storage and/or transportation can be achieved thus allowing greater flexibility for testing and potential reduction in costs.
TransFix® is used to stabilise whole blood for flow cytometry and blood donor screening, plus Cerebrospinal Fluid (CSF) (2), Bone Marrow and Fine Needle Aspirates. It is available in several formats including blood or CSF sample storage tubes, direct draw vacuum blood collection tubes, and bulk volumes.
Benefits of TransFix®
- Stabilises cell surface antigens for a minimum of 10 days at 2-22°C and for 4 days at 37°C. (1)
- Easy to use, just add TransFix® and mix by inversion
- Ensures sample integrity during transportation between clinical sites
- Eliminates the need for weekend and evening work
- Allows for repeat testing of samples without the need for patient recall and repeat phlebotomy
Whole blood degrades over time and blood samples older than 36 hours are no longer suitable for flow cytometric examination. Addition of TransFix® to blood samples at the time of collection has been shown to significantly extend the integrity of the samples. The immunophenotypic profile of markers including CD3, CD4, CD8, and CD45 is maintained for 10 days.
Sample Transport & Batching
The use of TransFix® is beneficial in situations where sample storage, batching or transportation is required prior to analysis. This may be particularly relevant in resource poor or remote areas of the world where there may be extended transit times between the phlebotomy site and laboratory. TransFix® treated samples may also be batched together before transporting, thereby reducing the number of shipments to the laboratory and thus reducing costs. In addition, the batching of samples for testing may result in reduced laboratory staffing costs.
TransFix® also reduces the need to recall patients for additional phlebotomy by extending the window of opportunity for sample testing, resulting in significant cost savings. This may be useful in circumstances where unexpected delays in testing have occurred, e.g. machine break down or transportation delay. TransFix® may also reduce the need for out of hours testing as treated samples can be stored until normal working hours. The use of TransFix® may therefore reduce the costs associated with out-of-hours testing.
Easy To Use
Samples should be treated with TransFix® as soon as possible after phlebotomy. Samples are added to TransFix® containing tubes and simply inverted and then stored at 2-8°C. The sample can then be treated as a “routine” preparation for subsequent analysis. The dilution factor must be taken into account when analysing absolute count data.
(1) Bergaron, M. et al., (2002), Evaluation of stabilised blood cell products as candidate preparations for quality assessment programs for CD4 T-cell counting. Cytometry, 50:86–91
(2) Sancho, JM. et al., (2010), Clinical significance of occult cerebrospinal fluid involvement assessed by flow cytometry in non‐Hodgkin's lymphoma patients at high risk of central nervous system. European Journal of Haematology, 85:312-328