Phospholipase C-labeled anti-human IgG: inhibition by human IgF.

We report here the inhibition of enzyme activity of phospholipase C-anti-human rabbit IgG conjugate complexed with human IgG. Phospholipase C activity was measured by assaying the release of hemoglobin from erythrocytes. The degree of inhibition varies depending on the relative amount of IgG utilized. A water soluble carbodiimide linking yields a conjugate which is inhibited by IgG, while conjugate prepared by glutaraldehyde is not. Immunodiagnostic assays requiring detection of low levels of antigen or antibody may be possible utilizing the phospholipase C-erythrocyte technique.