Sensitive enzyme immunoassay of cephalexin residues in milk, hen tissues, and eggs.
A sensitive enzyme immunoassay for cephalexin (CEX) was developed using the rabbit antiserum to CEX, beta-D-galactosidase-labeled CEX, and a double-antibody separation method. The immunogen of CEX was prepared by coupling the amino group of CEX to thiol groups introduced into bovine serum albumin by the use of N-(m-maleimidobenzoyloxy)succinimide as a cross-linker. Highly titered antiserum to CEX was produced in rabbits immunized with the immunogen. Enzyme labeling of CEX with beta-D-galactosidase was done by using N-(gamma-maleimidobutyryloxy)succinimide as the cross-linker. The limit of detection was 30 ng CEX/mL sample solution. Application of the method to CEX drug residues detected 30 ng/mL in milk, 60 ng/g in egg yolk, and 400 ng/g in hen tissue.
Kitagawa
T
T
Nagasaki University, Faculty of Pharmaceutical Sciences, Japan.
Gotoh
Y
Y
Uchihara
K
K
Kohri
Y
Y
Konoue
T
T
Fujiwara
K
K
Ohtani
W
W
D000818:Animals; D000918:Antibody Specificity; D002417:Cattle; D002506:Cephalexin / Q000032:analysis*; D002645:Chickens; D003429:Cross Reactions; D004350:Drug Residues / Q000032:analysis*; D004531:Eggs / Q000032:analysis*; D007124:Immunoenzyme Techniques; D008460:Meat / Q000032:analysis*; D008892:Milk / Q000032:analysis*; D013997:Time Factors; D001616:beta-Galactosidase
D001616:beta-Galactosidase; D002506:Cephalexin