[Analysis of the immunologic class of measles antibodies using protein A-producing staphylococci]

The suspension of staphylocci containing protein A in their cell walls (strain Cowan 1) has been used for the determination of the immunological class of measles antibodies in the blood of measles patients and healthy persons. Adsorption with staphylococcal reagent is a simple and precise method for the detection of IgM which cannot be detected at equal or higher IgG titers when the samples under study are treated with reducing substances similar to mercaptoethanol. The advantages given by the use of protein A preparations for differentiating the nature of serum antibodies are shown, which is essential for the diagnosis and epidemiological analysis of infectious diseases.