Prepared from Bovine Prothrombin through activation via the prothrombinase complex (FXa, FVa, PL and Ca++). Bovine a-Thrombin purity is determined by SDS-PAGE. This activated enzyme has a minmum activity of 1,800 NIH units/mg when compared to NIH standard human thrombin.

Activated Protein C is a serine protease derived from the two chain vitamin K dependent zymogen, Protein C. Activated Protein C inhibits blood coagulation through the selective inactivation of the cofactors Va and VIIIa. Activated Protein C is prepared from homogeneous protein C by activation with purified a-thrombin. This a-thrombin is removed after activation by ion exchange chromatography. Activated Protein C is homogeneous on 10% SDS-PAGE gels and shows complete reduction upon incubation with 2-mercaptoethanol.

Prepared from Bovine Factor IX by activation with Bovine Factor XIa. This Bovine Factor XIa is removed after activation. Complete activation is observed by SDS-PAGE. The Factor XIa activates Factor IX in a two step reaction. In the first step, an internal Arg-Ala bond is cleaved, and in the second step a Arg-Val bond is cleaved. The second cleavage leads to the liberation of an activation peptide from the NH2-terminal portion of the heavy chain to produce Factor IXa,b.

Bovine Factor Xa is prepared from Bovine Factor X by activation with Russell's Viper Venom (RVV-X). This RVV-X is removed after activation. Complete activation is observed by SDS-PAGE. Factor Xa, as part of the prothrombinase complex along with Factor Va, phospholipids and calcium ions, catalyses the rapid conversion of Prothrombin to Thrombin.

Bovine Factor XIa is purified from freshly collected bovine plasma using a combination of salt precipitations and activation on a negative surface. This Factor XIa is a potent activator of both Human and Bovine Factor IX. Bovine Factor XIa purity is determined by SDS-PAGE and shows complete reduction upon 2-mercaptoethanol.