Extraction and amplification of DNA from 55 foodstuffs

Abstract

With the enforcement of mandatory labeling of genetically-modified food in Europe, methods for their anal. are getting more and more important. Because of the nature of the genetic modifications, methods based on DNA anal. were developed first. In order to evaluate the extractability and the amplifiability of DNA, 55 food products derived from soybean, corn, potato, rice, sugar beet, tomato and wheat were analyzed for their DNA content. DNA fragments were subsequently amplified with PCR. In most cases where DNA was extractable, amplification was feasible with a eukaryote-specific PCR system. In addn., DNA of foods derived from corn, soybean and potato were amplified with a species-specific PCR for the detection of low copy no. genes. No DNA could be extd. from refined sugar and oil, whereas all other food samples yielded DNA. Furthermore, potato samples were extd. with the CTAB extn. method since the Wizard column method yielded only very low amts. of DNA. DNA can be extd. from a wide variety of foodstuffs and processing stages.