In the context of laboratory safety and aseptic technique, when must the cleaning step occur during microbiological procedures?

• A. Before and after handling microbial cultures
• B. Only if contamination is suspected
• C. Only after completing all experiments
• D. Only before starting any experiment

Answer: (A)

Verified step by step guidance

1. Understand the purpose of cleaning in microbiological procedures, which is to prevent contamination and ensure safety both for the experiment and the laboratory environment.
2. Recognize that microbial cultures can easily contaminate surfaces, tools, and hands, so cleaning must be done to minimize this risk.
3. Identify that cleaning before handling microbial cultures removes any existing contaminants that could interfere with the experiment.
4. Identify that cleaning after handling microbial cultures removes any microbes that may have been transferred during the procedure, preventing cross-contamination and maintaining safety.
5. Conclude that the cleaning step must occur both before and after handling microbial cultures to maintain aseptic technique and laboratory safety.