Activated Protein C Human Plasma. Activated Protein C, Source: Human Plasma, Physical Form Description: In 20 mM Tris-HCl, 0.1 M NaCl, pH 7.4, Molecular Weight: 56 kDa, Purity: greater than or equal to 95%, Synonyms: Vitamin K-dependent protein C, Anticoagulant protein C, Size: 50 ug