Albumin Density Gradient Separation and Washing of Platelets and the Study of Platelet Coagulant Activities

Abstract

Summary: Platelets were centrifuged into a specific gravity gradient made by mixing the interface between platelet rich plasma (PRP) and a 40–45% aqueous solution of bovine albumin. By this method of albumin density gradient separation (ADGS) it was possible to centrifuge platelets without disruptive squashing upon a hard surface. The separated platelets were washed in calcium‐free Tyrode's solution without releasing coagulant activity. Platelet yields after multiple washings were high. Morphology and ADP‐induced aggregation of platelets washed by ADGS (in contrast to platelets washed by conventional methods) were indistinguishable from those of unwashed platelets tested as PRP. The activities of factors V and XI remained in close association with platelets after four successive washes by ADGS, whereas factors VIII, IX and XII were entirely removed.