Detection of Listeria monocytogenes in foods by SYBR Green I melting curve

摘要

Two pairs of specific primers were composited based on the hlyA gene of L.monocytogenes and the 16sRNA gene of the genus Listeria. Optimal reaction system and condition of the SYBR Greenlfluorescent PCR were established, respectively, which could detect two specific genes. The reaction solution was verified by the method of gel electrophoresis. The results showed that two target fragments possessed different sizes and Tm valves which were amplfied corresponding two separate peaks. The standard curve based on the L.monocytogenes hlyA gene was established and the correlation coefficient was 0.996. The minimal detection limit was 89CFU/mL. Moreover, suspicious strain isolated from white clams was tested by using this method so as to study the feasibility. The positive result was evaluated with the National Standard Methods (GB 4789.30-2010). The verified result indicated that the positive result of SYBR Greenlfluorescent PCR matched with the GB 4789.30-2010 exactly.