What safety measures should be taken when handling microorganisms in a lab?

Using antibacterial spray and working by a lit flame is the appropriate safety measure when handling microorganisms in a lab. This practice helps maintain a sterile environment, which is crucial for preventing contamination of both the cultures and the workspace.

Antibacterial spray assists in disinfecting surfaces, effectively reducing the number of viable pathogens. Additionally, conducting experiments near a lit flame creates an updraft that helps prevent airborne contaminants from settling on open cultures or equipment. This combination of methods significantly enhances lab safety by minimizing the risk of cross-contamination and exposure to harmful microorganisms.

The other options do not provide adequate safety measures. For instance, wearing only gloves does not address contamination of surfaces and other equipment, while keeping cultures open exposes them to airborne contaminants. Lastly, wearing regular clothing lacks the protective qualities of lab coats or other appropriate attire designed to shield the wearer from spills and splashes, increasing the risk during handling.