CH50 method is used for the evaluation of complement system. In this method, sheep red blood cells (SRBCs) are sensitized with specific antibodies. Then, the capability of the complement system in the completion of the hemolytic reaction is assessed. In this study because of need for anti-SRBC antibody in CH50 test, it was produced in rabbit. This antibody is called “Amboceptor”.

 Materials and Methods

 In order to perform this study, SRBCs or their membrane antigens were injected into rabbits with different methods. Produced antibodies were analyzed in CH50 method using human pooled sera (derived from at least 15 blood donors). Finally the optical densities (ODs) related to the lysis of SRBCs were compared. It is obvious that the amount of OD is correlated with the efficiency of the antibody.

 Results

 Intravenous or intraperitoneal injections of SRBCs repeatedly result in the formation of high titer antibodies, but the rapid death of the animals due to the anaphylactic shock occurs. While the usage of sonicated or heat-treated antigens of SRBCs in the immunization leads to the formation of antibodies with high specificity and titer it does not threaten the life of the animals.

 Conclusions

 Production of anti-SRBC antibodies is applicable using different methods. This study shows that the use of the membrane or heat-stable antigens of SRBCs, which are prepared using sonication and heating (103ºC) respectively, has some advantages. These antigens are safe for rabbits and the titer of the antibody is high enough to be used in CH50 test.

 Key words: Forssman Antigen, CH50, SRBC