DNA Extraction from Bacterial Samples

A 350 μL aliquot of the homogenized sample was mixed with 0.9 volume of MagNA Pure Bacterial Lysis Buffer (Roche Applied Science, Indianapolis, IN), lysozyme (final concentration, 2.9 mg/mL; Sigma-Aldrich Corp., St. Louis, MO), and lysostaphin (final concentration, 0.14 mg/mL; Sigma-Aldrich), then incubated for 30 min at 37°C[23 (link)]. Samples were transferred to a tube containing 0.1 mm glass beads (MoBio Laboratories, Carlsbad, CA) and agitated in a Mini-Beadbeater-9 (Biospec Products Inc., Bartlesville, OK) for 1 min at the maximum setting. Samples were digested with Proteinase K (final concentration, 1 mg/mL) and incubated for 10 min at 65°C, agitated for an additional 1 min in the Mini-Beadbeater-9, and then incubated for an additional 10 min at 95°C. DNA purification was performed using an automated nucleic acid purification platform (MagNa Pure Compact System, Roche) using the manufacturer’s DNA Bacteria v3.1 protocol.