Serological diagnosis of Toxoplasma gondii infections by rapid separation of serum immunoglobulins M and G with CM Bio-Gel A

A simple and rapid method has been developed for the separation of serum immunoglobulin M (IgM) and IgG. CM Bio-Gel A chromatography was used in the technique, which resulted in an IgM-rich fraction containing 31% of the original serum IgM and less than 2% of the serum IgG. The procedure was used to detect masked IgM antibodies in patients suspected of having Toxoplasma gondii infections.