AN INTRALABORATORY QUALITY-CONTROL PROGRAM FOR QUANTITATION OF CD34-CYTOMETRY( CELLS BY FLOW)

This study was undertaken to develop a quality control protocol to mon itor instrument, operator, and CD34 assay performance, A dual level co ntrol system was established by cryopreserving aliquots of cells from peripheral blood progenitor cell (PBPC) collections exhibiting differe nt percentages of CD34+ cells. Twenty-five samples from each control s pecimen were assayed to establish a control range (mean +/- 2 SD), Lev ey-Jennings graphs were prepared for each control specimen to plot mul tiple measurements of CD34%, No significant differences were observed between fresh or cryopreserved PBPC aliquots in terms of light scatter properties or CD34 antigen density within the gated cell population, Cryopreserved PBPC samples are ideal for serving as a positive methodo logy control for daily CD34 analysis, Furthermore, such a system can h elp identify problems with assay reagents, sample preparation techniqu e, or incorrect data analysis.