Flow cytometry analysis of platelet TSP using the antibodies C6.7 and D4.6. Fifty microliters of PRP from heparinized blood was incubated at room temperature for 20 minutes with MoAb C6.7 (A) or D4.6 (B), with or without prior activation by A23187. (C) Shows the isotype specific control antibody, MOPC 21, which had been incubated with activated platelet. After a second incubation with FITC-labeled goat antimouse IgG the platelets were analyzed by flow cytometry as described in Materials and Methods. The log of fluorescence is indicated on the abscissa and cell count on the ordinate.