Premium
Detection of cows' milk in ewes' milk and cheese by a sandwich enzyme‐linked immunosorbent assay (ELISA)
Author(s) -
Rodríguez Elena,
Martín Rosario,
García Teresa,
González Isabel,
Morales Paloma,
Sanz Bernabé,
Hernández Pablo E
Publication year - 1993
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740610207
Subject(s) - antiserum , polyclonal antibodies , chemistry , antibody , chromatography , bovine milk , biotinylation , enzyme , food science , biochemistry , biology , immunology
A sandwich enzyme‐linked immunosorbent assay (ELISA) has been successfully developed for the detection of defined amounts of cows' milk in ewes' milk and cheese. Polyclonal antibodies were raised in goats against bovine caseins (BC). The resultant antibodies were recovered from the crude antiserum by ammonium sulphate precipitation and further purified by immunoatisorption of the cross‐reacting antibodies onto columns containing immobilised ovine, caprine and bovine caseins, followed by elution of the bovine caseins specific antibodies (anti‐BC) from the column containing the bovine caseins. The anti‐BC bound to the wells of a microtitre plate were used to capture the BC from milk and cheese mixtures. Further immunorecognition of the captured proteins was attained with the same specific antibodies conjugated to biotin. ExtrAvidin‐peroxidase was used to detect biotinylated antibodies bound to their specific antigens. Subsequent enzymic conversion of substrate gave clear absorbance differences when assaying mixtures of ewes' milk and cheese containing variable amounts of cows' milk.