Monoclonal antibodies for the analysis of gossypol in cottonseed products

Immunogens, prepared by conjugating either (+)-gossypol or (-)-gossypol to Limulus polyphemushemolymph protein, were used for immunization in the production of monoclonal antibodies. Hybridoma were evaluated for their relative affinity to racemic gossypol, (+)-gossypol, (-)-gossypol, gossypol analogues, and their lysine derivatives. The monoclonal antibody obtained showed higher affinity to gossypol and gossypol analogues as compared to their lysine derivative counterparts. An indirect competitive enzyme-linked immunosorbent assay (ELISA) with this antibody was used to measure gossypol in 15 cottonseed meal products; the results showed good correlation with results obtained using the AOCS (free gossypol) official method (R(2) = 0.89). The direct recognition of both free gossypol and bound gossypol using this antibody will be useful for rapid screening and quality control.