Abstract:To establish a PCR method for specific cod DNA detection, DNA sequences of pantophysin (Pan I) of four cod species, including those of Pacific cod (Gadus macrocephalus), Atlantic cod (Gadus morhua), Atlantic pollock (Pollachius pollachius), and Saithe (Pollachius virens), were obtained first from GenBank. The base sequence of the DNA of these four cod species was compared using Bioedit 7.0. According to the basic principles of primer design, cod fragments showing more significant base sequence differences from those of other fish species were selected for specific PCR primer design for the above-mentioned four cod species. These primers were used in the PCR amplification of DNA extracted from muscles and organ tissues of seven cod and fourteen other fish species. Combinations of two, three, and four primers were adopted for multiplex PCR experiments. The results showed clear 597, 392, 266, and 527 bp bands for Pacific cod, Atlantic cod, Atlantic pollock, and Saithe, respectively. In addition, no interference between the four primers was noticed, they are thus highly specific. The described method is highly sensitive and provides accurate results even for mixed samples with a concentration as low as 4 ng/μL.
