Enzyme-linked immunosorbent assay of neocarzinostatin chromophore (NCS-chr) by use of a monoclonal antibody against NCS-chr analog.

A monoclonal antibody against NCS-chr was prepared and characterized. Because of the instability of NCS-chr, chemically synthesized stable analog compound, termed PS, was used as a hapten of immunogen. The obtained antibody, termed APS, reacted with NCS-chr, but neither with NCS, NCS-polystyrene-maleic acid conjugate (SMANCS), nor UV-irradiated NCS-chr. Epitope analysis using the compounds that have a structure similar to PS showed that APS recognized the total structure, particularly cyclopenten moiety, of PS. These results suggest that APS recognizes the enediyne structure of NCS-chr. Next, the inhibition enzyme-linked immunosorbent assay (ELISA) for determination of NCS-chr was established. The standard curve showed that the microgram order of NCS-chr were accurately measurable by the established ELISA. Furthermore, it was revealed that the established ELISA was more sensitive than the antibiotic activity determination, termed Bio-assay. The established ELISA will be useful as a quantitative method of NCS-chr.