Listeia monocytogenes is a not admitted bacterium in animal products, and its detecting needs long time and high costs for culture media and isolation. These are the reasons that imposed to find a cheaper and a more rapid method for detecting this bacterium. Microdetection using PCR is such a method. This method uses primers (oligonucleotide segments) complementary to a strict specific DNA segment from researched cell, named target - segment. After both complementary segments linkage product is over a million times amplified using an enzyme (polymerase), and then emphasized by electrophoresis and photo in UV spectrum. Using PCR the identification time of L.monocytogenes is 5 - 10 times reduced as compared to classical method, and also permits to renounce to special identification and isolation media, the efficiency of this method being obvious.
