AIM To determine the activities of antibodies (hemolysin) against sheep red blood cells (SRBC). METHOD Serum samples
containing
hemolysin were pre diluted. Then 100 μl of each diluted samples was transferred into the wells of a 96 well plate for further limited serial dilution with two fold each time. After that each well received 50 μl of 1 5% SRBCs and 1∶10 diluted guinea pig sera respectively. After incubation for 1 to 12h at 37℃ the SRBCs in the wells
containing enough amount of hemolysin were completely lysed and the bottoms of the wells could be thoroughly transparent. However, the SRBCs in the wells containing less amounts of hemolysin were only partially lysed and with the blockade of the remaining intact SRBCs the transparency of the bottoms was impared to some extent. The hemolysin activities of samples were determined by the combination of the transparent degrees of the wells with the known diluted times. Under the plate a test sheet on which the capital letter “R”s had been printed was placed for transparency determination. RESULTS The assessed values were well lineally correlated with the theoretical ones and the results obtained by the method for several drugs were in accordance with those by spectrophotometry.CONCLUSION The procedure of the method is simple and the results are quickly obtained, accurate and reproducible.