Zymogram of native platelets (A) and scu-PA–enriched platelets (B) after incubation with plasminogen and S2403 in the absence or presence of thrombin. Lane 1 contains MW standards; lanes 2 to 7 are platelets after 1 hour; and lanes 8 to 13 are platelets after a 5-hour incubation with thrombin, 0,2,8 1 U/mL,3,9 2.5 U/mL,4,10 5 U/mL,5,11 10 U/mL,6,12 or 40 U/mL.7 13