title: Simple method for demonstrating small plasmid deoxyribonucleic acid molecules in oral streptococci.
abstract: A simple procedure for rapidly demonstrating small plasmids (less than 10 megadaltons) in oral streptococci is described. Logarithmic-phase, glycine-treated cells from 1.5-ml broth cultures were converted to osmotically fragile forms and lysed with sodium dodecyl sulfate. After the hydrodynamic shearing of host chromosomal deoxyribonucleic acid, such lysates were analyzed by low-voltage agarose gel electrophoresis. Small plasmids, migrating significantly faster than chromosomal deoxyribonucleic acid under such conditions, were readily visualized by ethidium bromide staining.
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis*; D004587:Electrophoresis, Agar Gel / Q000379:methods; D006801:Humans; D010957:Plasmids; D013291:Streptococcus / Q000235:genetics*; D013295:Streptococcus mutans / Q000235:genetics*; D013298:Streptococcus sanguis / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial