Detection and quantification of goat's cheese in ewe's cheese using a monoclonal antibody and two ELISA formats

A stable hybridoma cell line (B2B) has been produced secreting a monoclonal antibody (MAb) specific for the s alpha(s2)-casein of goats. The MAb B2B w as used in two enzyme-linked immunosorbent assays (ELISA) formats for the d etection and quantification of the presence of goat's cheese in ewe's chees e samples. In the indirect ELISA format the limit of detection was 1-25% (w /w) substitution of ewe's cheese samples by goat's cheese. Afterwards, a co mpetitive indirect ELISA was successfully developed for the detection of 0. 5 to 25% (w/w) of goat's cheese in ewe's cheese samples. This competitive i ndirect ELISA is a very sensitive assay, can be performed in less than 5 h and is not influenced by the ripening process in cheese. (C) 1999 Society o f Chemical Industry.