[A rapid method for the determination of virus-specific IgM antibodies].

A newly developed ion exchange chromatography is reported; it is a simple and quick method to separate a highly purified IgM fraction from blood serum. The immunofluorescence test was used to demonstrate that these fractions contain only virus-specific IgM antibodies, but no demonstrable IgG antibodies, which can often block the specific IgM reactivity by competitive inhibition. The specificity of the reaction was tested on sera from 145 persons: the IgM test was always positive in clinically proven viral infections; the reaction was negative in all patients whose infection had occurred some time in the past. A series of suspected virus infections could be verified by the demonstration of specific IgM antibodies.