Identification of Radiation Treatment of Frozen Chicken and Fresh Turkey using DNA Comet Assay

Abstract

DNA comet assay was applied to check the detection of radiation treatment of frozen chicken and fresh turkey. The cells from unirradiated and irradiated samples of chicken and turkey were extracted in cold PBS, embedded in agarose on microscope slides, lysed for 15 minutes in 2.5 % SDS and subjected to electrophoresis at a rate of2V/cm for 2 minutes. After silver staining these slides were evaluated through an ordinary transmission microscope. In irradiated samples, fragmented DNA (due to radiation treatment) stretched towards the anode and cells appear as comets. The density of DNA material in the tails increased with increasing radiation dose. However in case of unirradiated samples, the large molecule of DNA remained relatively intact and there was only minor or no migration of DNA; thus cells were round or had very short tails. Therefore, clear discrimination between unirradiated and irradiated food samples is possible. Hence, DNA comet assay provides an inexpensive and quick screening method for several kinds of foods containing DNA including frozen chicken and fresh turkey