cDNA is the abbreviation for complementary DNA: single stranded DNA formed from an mRNA template by reverse transcriptases. Radiolabelled cDNA can be used as a probe in genetic techniques, binding to matching sequences to reveal their presence. In food science, cDNA tools detect pathogens, allergens and GM traits, support the study of genes behind flavour, ripening and fermentation, and underpin diagnostic kits used in food safety laboratories worldwide. These tools let a single test screen for multiple hazards, speeding up food-safety decisions.