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

¹ Endocrinology-Reproductive Physiology Program and Department of Dairy Science, University of Wisconsin-Madison, Madison 53706

Enzyme-linked immunosorbent assays for bovine -lactalbumin and ßlactoglobulin have been developed for measurements of serum and tissue culture samples. Either -lactalbumin or ß-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 -lactalbumin or ß-lactoglobulin ELISA. Parallel curves from serial dilutions were obtained in serum and media samples. The additivity of -lactalbumin and ß-lactoglobulin ELISA was validated in either serum or medium samples. The intraassay and interassay coefficients of variation for -lactalbumin and ß-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.

Key Words: enzyme-linked immunosorbent assay • -lactalbumin • ßbeta;-lactoglobulin

Submitted on December 7, 1990
Accepted on April 15, 1991