Rapid detection of bovine milk in yak milk using a polymerase chain reaction technique

Sequence alignment of ND1 gene fragment from bovine and yak. Large open arrows indicate the 2 primers common to both bovine and yak (BO/YA-FW and BO/YA-RV); the narrow black arrow indicates the bovine-specific primer (BO-FW). In the position of primer BO-FW, nucleotides that differ between bovine and yak are boxed.

Electrophoretic analysis of the ND1 gene PCR amplification fragments obtained from bovine (lane 1 and 3) and yak (lane 2 and 4) milk DNA using primers BO/YA-FW and BO/YA-RV. M=molecular weight marker, 100-bp DNA ladder (TaKaRa, Dalian, China); N = negative control.

Electrophoretic analysis of the bovine-specific ND1 gene amplification from milk samples using primers BO-FW and BO/YA-RV. Samples are bovine (lanes 1, 3, and 5) and yak (lanes 2 and 4). M=molecular weight marker, 100-bp DNA ladder (TaKaRa, Dalian, China); N=negative control.

Electrophoretic analysis of the ND1 gene PCR amplification fragments obtained from bovine (lane 2), yak (lanes 1, 3, and 7), and binary mixture of bovine/yak milk containing 50% (lane 4), 20% (lane 5), and 5% (lane 6) bovine DNA using primers BO/YA-FW, BO-FW, and BO/YA-RV. M=molecular weight marker, 100-bp DNA ladder (TaKaRa, Dalian, China); N=negative control.

Electrophoretic analysis of the ND1 gene PCR amplification fragments obtained from raw milk binary mixtures of bovine in yak by using primers BO/YA-FW, BO-FW, and BO/YA-RV. Samples are 100% bovine (lane 1), 10% bovine (lane 2), 5% bovine (lane 3), 1% bovine (lane 4), 0.5% bovine (lane 5), 0.1% bovine (lane 6), and 100% yak (lane 7). M=molecular weight marker, 100-bp DNA ladder (TaKaRa, Dalian, China); N=negative control.