Enzyme-Linked Immunosorbent Assays for Bovine α-Lactalbumin and β-Lactoglobulin in Serum and Tissue Culture Media

Abstract

Enzyme-linked immunosorbent assays for bovine α-lactalbumin and β-lactoglobulin have been developed for measurements of serum and tissue culture samples. Either α-lactalbumin or β-lactoglobulin antiserum was coated on ELISA plates. Biotinylated proteins were used in competition with unknown amount of proteins in samples. After unbound proteins were washed off, ExtrAvidin-peroxidase and tetramethylbenzidine were then used as a detection system. Crossreactivity of caseins or bovine serum albumin was less than .0001% in either α-lactalbumin or β-lactoglobulin ELISA. Parallel curves from serial dilutions were obtained in serum and media samples. The additivity of α-lactalbumin and β-lactoglobulin ELISA was validated in either serum or medium samples. The intraassay and interassay coefficients of variation for α-lactalbumin and β-lactoglobulin ELISA were below 10% over 51 and 47 assays. The ELISA are useful in mammary gland biology studies for measuring milk whey protein in serum or culture media. © 1991, American Dairy Science Association. All rights reserved.