Use of a monoclonal antibody and two enzyme-linked immunosorbent assay formats for detection and quantification of the substitution of caprine milk for ovine milk

Abstract

A stable hybridoma cell line (B2B) has been produced that secretes a monoclonal antibody (MAb) specific for goat's milk α(S2)-casein. The MAb B2B was used in two enzyme-linked immunosorbent assay (ELISA) formats for the detection and quantification of the presence of goat's milk in ewe's milk. In the indirect ELISA format the limit of detection was 0.5 to 15% (vol/vol) substitution of goat's milk for ewe's milk. Afterwards, a competitive indirect ELISA was successfully developed for the detection of 0.25 to 15% (vol/vol) of goat's milk in ewe's milk. This competitive indirect ELISA is a very sensitive assay; it can be performed in less than 5 h and is not influenced by the heat treatment of milk.