Abstract: The genome DNAs of Salmonella and some control bacteria were extracted by CTAB/NaCl method. The multiplex PCR methods detecting synchronously among Salmonella genus special genes such as hut gene(495bp), hilA gene(490bp), invA gene(284bp) and hns gene(152bp) were developed by optimizing the concentration of primers and the unit of Taq DNA polymerase, and the detection limits were tested. The results showed that the detection results by multiplex PCR methods developed were same as expect, and the detection limits of the duplex PCR was same as those of single PCR, while those of triplex PCR were declined.

Key words: Salmonella, genome DNA, multiplex PCR, detection limit