Screening maize food products sold in Brazil from 2005 to 2007 for the presence of cryIA(b) gene and P35S promoter

Abstract

Screening systems for genetically modified organisms (GMOs) detection by polymerase chain reaction (PCR) have been developed to detect commonly used elements in genetic engineering, such as the promoter and the terminator. In the present investigation, PCR method was applied in order to detect CaMV 35S promoter (P35S) and cryIA(b) gene in 68 food samples (15 maize flour, 23 corn meal, 10 maize flour flakes and 20 polenta) commercialized in Brazil from 2005 to 2007 and 2 food samples commercialized in Argentina (1 maize flour and 1 polenta). The DNA from maize samples was extracted using CTAB and the presence of amplifiable maize DNA was showed by the amplification of invertase and zein gene fragments. Out of 68 Brazilian samples analyzed, 18 were positive for cryIA(b) gene and one was positive for both cryIA(b) gene and P35S promoter. For Argentinean samples, both were positive for cryIA(b) gene and P35S promoter.