Sandwich immunoassay and compositions for use therein

摘要

An improved sandwich immunoassay for Toxoplasma gondii antigens associated with acute forms of Toxoplasma infection is disclosed. The assay employs either an F(ab')2 fragment of IgG which reacts specifically with such antigens or a monoclonal antibody for such antigens as the substrate layer in the sandwich. The assay is sensitive and, unlike prior sandwich assays for the antigen, is not affected significantly by cross-reactions with rheumatoid factor.