Detection of pork in heated meat products by the polymerase chain reaction

A new method for the specific, sensitive, and semiquantitative detection of pork (Sus scrofa) in heat-treated meat products has been developed. DNA was isolated from meat samples by using a DNA-binding resin and subjected to polymerase chain reaction (PCR) analysis. First, oligonucleotides yielding a specific 137-base-pair (bp) fragment from eucaryotic DNA amplified from a highly conserved region of the 18-S ribosomal gene was used to assess DNA quality. Second, the presence of pork DNA was determined with specific oligonucleotides yielding a 108-bp fragment amplified from the porcine growth hormone gene. The test detected pork in fresh or heated meat mixtures of pork in beef at levels below 2%. This approach was superior to commercially available immunological tests that were not able to detect levels of pork less than 20% in cooked meat or less than 10% in fresh meat.