DNA homologies among Eikenella corrodens strains

Deoxyribonucleic acids were extracted from 22 Eikenella corrodens strains of human oral origin. The DNA's were compared by determination of their base contents (mol % G + C), and by DNA hybridization on membrane filters and in solution using Sl nuclease. DNA was radioactively labeled in vitro by use of DNA polymerase and labeled triphosphate bases. On membrane filters, DNAs hybridized at least 70 % with labeled strains. Mean base contents were between 55.7 and 57.2 mol % G + C with an overall mean of 56.3. It was found that the labeled DNA was somewhat sensitive to Sl nuclease and this produced variations in hybridization when the Sl method was used although no heterogeneities were apparent. The strains had similar biochemical properties. They produced only slight amounts of acetic acid in Todd‐Hewitt broth. These human oral strains appeared to be a biochemically and genetically homogenous group.