[Flow cytometry combined assay for phosphatidylserine and CD62p expressed by preserved platelets]

Human platelets have distinct characters when preserved by different methods. A efficient flow cytometric assay for different preserved platelets expression of CD62p and phosphatidylserine(PS) is in dire need. Efficient flow cytometric assay for CD62p and PS expressed by preserved platelets was established and the major conditions were optimized. The platelets need not to be washed to wipe off plasma and can be labelled diredtly during the sample preparation. It is efficient for flow cytometric analysis when fresh platelet riched plasma (FPRP) was set as negative control, thrombin actived FPRP, and liquid nitrogen treated FPRP were set as positive control respectively. Gly-Pro-Arg-Pro acetate salt (GPRP) was applied to prevent platelets aggregation and fibrin formation, stabilize platelets and minimize the artificial platelets activation. This is also the key to conquer difficulty of flow cytometric quantitive analysis when platelet, Ca(2+) and plasma coexist. This flow cytometric method is specially suitable for the multi-parameter assay including PS expression for cryopreserved platelets. Minimal sample manipulation, no fixation, and GPRP application resulted in minor artifacts and good sample stability. Results suggested, this flow cytometric assay for preserved platelets is simple and efficient. In addition, the author prepared four different methods treated platelets that can be easily distinguished through this flow cytometric assay. It not only makes sure the practicability of this flow cytometric assay, but also suggests the value of the treated platelets applied in preserved platelets flow cytometric ass