[Studies on optimising rubella virus haemagglutination-inhibitor tests].

Immuno-electrophoretic and serological studies were undertaken to characterise the non-specific serum inhibitor of rubella haemagglutination. The majority of such inhibitor effects come from the beta(1)-lipoproteins. In addition, small inhibitory effects which were due to alpha(1)-lipoproteins were noted in some sera. The result of the tests is influenced less by removing the inhibitor than by conditions of incubation of the serum-antigen mixture, especially pH. The test is more sensitive if it is not performed at optimal pH for haemagglutination.