The current investigation was carried out for 100 random sample of meat products represented by frozen beef burger, frozen kofta, minced meat and oriental sausage (25 each) gathered from various shops and retail stores in Menofya governorate. The gathered samples were subjected to bacteriological examination for the isolation and identification of non O157 E.coli and E.coli O157 by using Conventional and recent techniques as multiplex PCR. By the conventional method the incidence of E.coli in the tested samples of beef burger, kofta, minced meat and oriental sausage was 6(24%), 9(36%) , 5(20%) and 11(44%) respectively. Multiplex-PCR technique was applied on 10 random meat product samples (3 negative and 7 positive for the isolation of E.coli by conventional method). M-PCR technique was applied in order to detect stx1 and stx2. In this study ,the M-PCR give negative result with all tested food samples. This study clarified that multiplex PCR may give negative results due to inhibitors that can be found in microbial DNA solutions extracted from meat sample or due to inhibitors which added during processing of meat products .