ABSTRACT
An internal amplification control, which could be co-amplified with the invA target gene of Salmonella in the PCR system, was constructed in order to indicate possible PCR inhibitors derived from food samples. Specificity of this PCR system was tested with 9 Salmonella strains and 15 non-Salmonella strains, and the results showed that there was a 374 bp amplicon resulted from all Salmonella strains, while only a 513 bp IAC amplicon appeared after the amplification for all non-Salmonella strains. The detection sensitivity of this PCR system was 12.8 fg/?L for purified target DNA, and the detection limit for artificially inoculated milks was 8 cfu /25g if they were enriched for 8h in buffered peptone water. Salmonella in 80 samples of seriously contaminated milks was detected by the PCR method developed in this study, and the experiments demonstrated that it could successfully eliminate false-negative results.