Experience With a Modified Rubella Hemagglutination Inhibition Antibody Test

This report confirms the value of a modification of the rubella hemagglutination inhibition (HI) antibody test which has eliminated the source of a troublesome problem, the random, unpredictable appearance of false positive results caused by inadequate removal of nonspecific serum inhibitors of hemagglutination. The modification consists of pretreating the test sera with a solution of manganese chloride and heparin sodium instead of kaolin suspension. The procedure is also more sensitive, rapid, and convenient, even in the hands of less experienced personnel, and should remove the last technical barrier to widespread availability of laboratory serodiagnosis for rubella. Furthermore, its use with 2-mercaptoethanol extends the range for accurate retrospective diagnosis of recent rubella.