Absorption of IgG does not enhance toxoplasma IgM and IgA immunoblotting

1 Microbiology Department, Raigmore Hospital NHS Trust, Inverness IV2 3UJ 2 Department of Medical Microbiology, University of Aberdeen, Foresterhill, Aberdeen AB9 2ZD 3 Corresponding author: Dr J. M. W. Chatterton. Received March 19, 1998 Accepted September 29, 1998 Total IgG, IgM and IgA levels and toxoplasma IgG. IgM and IgA immunoblotting patterns were assayed in 10 sera before and after IgG absorption with Protein G -Sepharose 4. Removal of IgG (mean reduction 96%) was accompanied by a significant reduction in the level of IgM (mean reduction 56%) and IgA (mean reduction 53%) in nine of the 10 sera. The absorbed supernates showed fewer and weaker IgM bands in five sera, but IgA immunoblotting patterns were unaffected by absorption. There was no benefit in removing IgG in toxoplasma IgM and IgA immunoblotting.