Key points are not available for this paper at this time.
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.
Broekman et al. (1975) studied this question.