Specific and nonspecific endoglycosidase digestion of control and PV platelet lysates. Platelet lysates from a control and 3 different patients were untreated (lanes 1 to 4), digested with endoglycosidase H (lanes 5 to 8), or digested with N-glycosidase F (lanes 9 to 12), and subsequently probed with the Mpl C-terminal antiserum.