Distribution of Fibrinogen, and Platelet Factors 4 and XIII in Subcellular Fractions of Human Platelets

Abstract
The distribution of fibrinogen, platelet factor 4 (heparin-neutralizing factor) and factor XIII amongst subcellular fractions of human platelets was determined. It was found that fibrinogen and platelet factor 4 peaked sharply in the region of the density gradient previously shown to be heavily enriched with alpha-granules. By contrast, factor XIII, fibrin-stabilizing factor, was found exclusively in the supernatant.