A COMPARISON OF ABSOLUTE COUNTING PARTICLES FOR QUANTIFICATION OF CELLULAR SUBSETS BY FLOW CYTOMETRY IN DRUG DEVELOPMENT

Rationale: Flow Cytometry can be used to measure relative percents of many leukocyte subsets. The measurement of absolute counts, of these same subsets, can be challenging if hematology data is not available. Many commercial vendors have developed particles, which when added to whole blood specimens can provide absolute counts, eliminating the need for hematology data. The purpose of this experiment was to compare absolute counting particles from four different vendors to determine if they compare for quantifying counts in the standard T-cells and subsets, B-cells and