A test system based on DNA probes is a specific approach to detect microbial contamination of food products. Selection of probe, sample preparation, hybridization methods and detection of hybrids will be described as well as the application of DNA probes in food microbiology. Non‐isotopic tests forSalmonella,Listeria,Yersinia,Campylobacterand enterotoxigenicEscherichia coliare already or will soon be commercially available.