The latent and polymerized conformations of antiplasmin are present in S/D plasma. Western blot analysis of plasma proteins. (A) Nondenaturing-PAGE: (1) antiplasmin in FFP; (2) antiplasmin in FFP following S/D treatment in our laboratory (see Materials and Methods); (3) antiplasmin in S/D plasma; (4) antiplasmin in FFP diluted 10-fold more than lane 1. (B) SDS-PAGE with molecular weight standards as indicated: (1) antiplasmin in FFP; (2) antiplasmin in S/D plasma. (C) Nondenaturing-PAGE of S/D plasma containing aggregates: (1) antiplasmin in S/D plasma after removal of aggregates; (2) antiplasmin in aggregates isolated as described in Materials and Methods.