Briefly, the
cells from 1.5 ml of MRS broth were pelleted by centrifugation, the
total DNA was extracted and fragmented with HindIII restriction
endonuclease, the resulting DNA fragments were resolved by
agarose gel electrophoresis, and blotted onto a nylon membrane
Southern blots were hybridized with digoxigenin-labeled probes,and the labeled fragments were detected and visualized to reveal a ribotyping fingerprint.