Comparisons with other proteomes. The Venn diagrams in the figure indicate how many of the 69 membrane proteins identified in the present study were detected in (A) a study of proteins in which the starting material was isolated in platelet membranes and (B) 3 studies of either isolated platelet α-granules or platelet releasate. In the releasate studies, platelets were incubated with an agonist for 5 minutes or less, considerably shorter than the 60-minute incubation adopted here to allow time for delayed shedding to proceed to or close to completion.