USE OF A HETEROLOGOUS SOLID-PHASE ANTIGEN IN AN INDIRECT COMPETITIVE ANTIBODY-CAPTURE ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR T-2 MYCOTOXIN

Anti-T-2 toxin (T-2) antibodies raised in chicken hosts were isolated as total IgY (chicken immunoglobulins of IgY isotype) from serum and t he egg yolk. They were used for quantitation of T-2 toxin in an indire ct competitive enzyme-linked immunosorbent assay (ELISA) which employe d molecularly distinct toxin-carrier conjugates as solid-phase assay a ntigens. The sensitivities of the assays utilizing any of the purified IgY or unfractionated serum were similar but varied with respect to t he type of conjugate used and could be improved by lowering the concen tration of assay antigens or antibodies. Low concentrations of both im munoreactants resulted in assays of superb sensitivity, although the s tandard curves generated with some assay antigens decreased markedly i n slopes and impractically long incubation times were required to deve lop sufficiently high read-out signals. However, high optical signals were obtained in a very short period of time when an amplified substra te system instead of para-nitrophenyl phosphate (pNPP) was used for th e detection of a reporter enzyme, alkaline phosphatase. The use of an amplified substrate and of a solid-phase antigen that was prepared wit h Iso T-2 toxin attached directly to a carrier protein yielded an ELIS A that had an improved ability to detect T-2.