Heat inactivation of serum is performed at:
Freshly collected fetal bovine serum contains intact complement system cascade components of innate immunity capable of opsonization, chemotaxis, and direct lysis. Components include classical pathway C1 complex C1q six headed collagen-like recognizing immune aggregates, C1r C1s serine proteases cleaving C4 C2 forming C3 convertase C4b2b, alternative pathway factor B D, lectin pathway mannose binding lectin MBL associated serine proteases MASP, central protein C3 three chain alpha beta gamma 185 kDa convertible to active C3b depositing via thioester covalent attachment onto cell surface hydrox
Ref: Gibco FBS heat inactivation 56°C 30 min complement C2 denaturation; Abbas Immunology complement C1q classical pathway removal.