Hi all Our standard method for CD34 enumeration is a dual platform ISHAGE gated (wash) method. In order to establish and validate a single platform (no wash) ISHAGE method in the laboratory, it would be nice to be able to run an internal control. I have used Beckman-Coulter's commercial Stem-Trol control cells for this purpose, but have been unable to recover the stated assayed concentration. In fact I my determinations are consistently higher than the allowable +/- 15% range. Apart from some difficulties in gating placement, as these cells display increased forward and side light scatter characteristics to normal human haematopoetic precursors, I cannot see why my results are too high (around 40% above the stated concentration). I practice reverse pipetting, and mix the fluorospheres adequately prior to dispensing. Single vs dual platform comparisons for peripheral blood demonstrate a small positive bias in favour of the single platform method, whereas results are identical for apheresis product. In addition, the absolute CD45+ count is in general agreement with the analyser WBC count. I would like to ask: What is the group experience with the use of internal controls for CD34 enumeration, and in particular with Stem-Trol cells? Is the stated Stem-Trol assayed concentration and range reflective of common experience? Are internal CD34+ controls regularly utilised in routine practice? What alternative sources are available? Thanks Emanuel Raniolo IMVS Laboratories The Queen Elizabeth Hospital Department of Haematology Cell Analysis and Cryopreservation Laboratory Adelaide, South Australia.
This archive was generated by hypermail 2b29 : Sun Jan 05 2003 - 19:01:41 EST