TECHNICAL NOTE - DETECTION OF BOVINE KAPPA-CASEIN VARIANT-A, VARIANT-B, VARIANT-C, AND VARIANT-E BY MEANS OF POLYMERASE-CHAIN-REACTION SINGLE-STRAND-CONFORMATION-POLYMORPHISM (PCR-SSCP)

We used polymerase chain reaction single strand conformation polymorph ism (PCR-SSCP) analysis to screen the most frequent variants (A, B, C, and E) found in the bovine kappa-casein gene. The PCR products (453 b p) were heat-denatured, loaded onto nondenaturing polyacrylamide gels, and silver-stained. Each variant yielded patterns clearly distinguish able from the others. Optimal conditions for the simultaneous detectio n of the four variants were 12% polyacrylamide gels (100:1 acrylamide: bis-acrylamide ratio) with 5% glycerol and a constant running temperat ure of 10 degrees C. Eight reference samples initially used for this p urpose and 40 anonymous samples of different cattle breeds diagnosed b y PCR-RFLP and PCR-SSCP showed no discrepancies between the two method s and confirmed previous results. Because it is cost-effective, sensit ive, and fast, PCR-SSCP is strongly recommended to routinely screen ka ppa-casein variants for industrial purposes or in cattle selection sch emes.