If food was cultured for 25 hours for proliferation in listeria enrichment broth, then the culture was chemically extracted, the purified bacteria after heat lysis could react as PCR templates and the inhibitory effects could be greatly reduced.

• 经过25小时的增菌培养，对培养物进行化学抽提、纯化的菌体经加热裂解后直接用作pcr反应模板，可使抑制作用大大降低。