The effect of six common PCR inhibitors on DNA polymerase and DNA template

In order to elucidate the effect of PCR inhibitors on DNA polymerase and DNA template, two main components of the PCR reaction, in this paper, we selected six representative PCR inhibitors, bile salts, collagen, humic acid, hemoglobin, melanin and urea, and added respectively them to the K562 DNA with the standard addition concentration in which all of 26 different alleles of the K562 DNA with the AmpFℓSTR® Identifiler® PCR Amplification Kit are just inhibited completely. On this basis, after increased the amount of K562 DNA and DNA polymerase respectively, PCR amplification and STR genotyping were performed, and then counted the allele number of K562 DNA detected. When the DNA polymerase was increased to a certain amount, all of 26 alleles of the K562 DNA mixed with various PCR inhibitors could be detected successfully, and when the amount of K562 DNA was increased, the inhibitory effect of bile salts, collagen and urea had only been eliminated partly and no significant improvement was observed for the other three inhibitors. The results indicate that all of the six representative PCR inhibitors mainly inhibit DNA polymerase, and increasing the amount of DNA polymerase in PCR reaction can improve significantly the efficiency of PCR amplification and the success rate of genotyping