An improved method for increasing the sensitivity of direct agglutination test (D.A.T.) to the detection of IgM and IgG anti-toxoplasma antibodies.

: The present investigation has shown that the antibody titers obtained by IgG-IFA correlate well with 2-ME-DA (correlation coefficient 0.927, p less than 0.001). These results are obtained when the antibody titers are expressed as IU/ml. Buffer without 2-ME and purification of IgM fractions by simple gel-filtration method seem to be necessary conditions for detecting IgM antibodies by DA test in adult patients. Therefore the DA with these micromodifications has a specificity and sensitivity similar to those of IgG and IgM-IFA tests and would be convenient for laboratories that perform large scale surveys during pregnancy.