A researcher is evaluating the antibacterial properties of different formulations of tea tree oil against Staphylococcus aureus.
During the preparation of the agar plates, the researcher disinfected the laboratory bench with 70% ethanol and carried out all transfer steps within the updraft of a lit Bunsen burner.
State one other aseptic technique the researcher should use during the inoculation process to prevent contamination of the nutrient agar.
