Hemolytic assay of complement and its components from Syrian hamster (Mesocricetus auratus) and Mongolian gerbil (Mariones unguiculatus).

Syrian hamster sera may be assayed for hemolytic complement (C) activity by standard procedures with sensitized sheep erythrocytes as used for human sera, but mongolian gerbil sera had higher complement titers when tested with sensitized guinea pig erythrocytes as target cells. The optimal conditions for in vitro testing of hamster C were pH 7.3, ionic strength 0.15, and presence of 1 micrometer of Mg2+ and 0.3 micrometer Ca2+. For gerbil C the optimum pH was 8, ionic strength 0.074, and the same concentration of Mg2+ and Ca2+ as for hamster. Incubation at 37 degrees C for 60 minutes yielded optimal results. Complement components in the serum of both species could be tested with commercially prepared intermediates of sheep erythrocytes pretreated with guinea pig C1 and human C4 respectively, using purified human C2 through 9 and standard methods applied for testing human C components. Both species have all nine components of the complement system.