Immunoperoxidase localization by electron microscopy of soluble egg antigen and human IgG in circumoval precipitin reactions around Schistosoma mansoni eggs.

Soluble egg antigen and human IgG were localized by the unlabelled antibody enzyme technique for electron microscopy on Schistosoma mansoni eggs having circumoval precipitin reactions. Reaction products indicating the presence of soluble egg antigen were on portions of the circumoval precipitate outside the egg, between the eggshell and vitelline membrane, and between the vitelline membrane and miracidium inside the egg. Reaction products indicating human IgG were only found on portions of the circumoval precipitate external to the eggshell.