A simple, sensitive, dried gel DNA hybridization method for detection of Listeria monocytogenes DNA fragments is described. DNA samples were fractionated on an agarose gel. The gel was then denatured in NaOH-NaCl and neutralized in Tris-NaCl. The resulting agarose gel was dried and hybridized with 32P-labelled DNA probe. No transfer to nitrocellullose membranes was used.