Enhanced sensitivity in PCR detection of Listeria monocytogenes in soft cheese through use of an aqueous two-phase system as a sample preparation method.

A sample treatment method based on an aqueous two-phase system containing polyethylene glycol and dextran was developed for enhancing sensitivity in the detection of Listeria monocytogenes in soft cheese with PCR. The results suggest that the improved detection sensitivity following partitioning of the cheese homogenate in an aqueous two-phase system may be due to partitioning of the PCR inhibitors to the polyethylene glycol phase.