Separation of rubella IgM, IgA, and IgG antibodies by gel filtration on agarose

Abstract

Identification of the immunoglobulin classes of rubella antibodies is the only reliable tool for the diagnosis of a recent primary infection with rubella within 6-8 weeks of infection. Gel filtration permits the separation of IgM and IgA antibodies, both characteristic for a recent infection, from persistent rubella IgG antibody (which indicates pre-existing immunity). Gel filtration on agarose offers advantages over the other methods for separating immunoglobulin classes. Fractionation of specific rubella antibodies is important not only in all cases where a serum sample was taken too late and a rise of antibody titre missed, but also in cases with significant antibody rise to distinguish a secondary immune response after rubella reinfection.