Effect of irradiation on the detection of bacterial DNA in contaminated food samples by DNA hybridization

A membrane-based DNA hybridization technique was used in a model system to examine the effect of irradiation treatment on the detection of bacterial contamination in foodstuffs. Although hybridization signals were reduced compared with otherwise identical unirradiated food samples, artificial contamination levels in excess of 10⁵ cfu per test could be distinguished in 12 of the 13 foods examined following the irradiation process. In no case were viable bacteria detected following irradiation treatment.