Which of the following is NOT an effective way to avoid the temperature danger zone in microbiology laboratory settings?

• A. Refrigerating samples at 4°C
• B. Leaving samples at room temperature for extended periods
• C. Incubating cultures at 37°C
• D. Storing media in a freezer at -20°C

Answer: (B)

Verified step by step guidance

1. Understand the concept of the temperature danger zone in microbiology, which typically ranges from 5°C to 60°C. This is the temperature range where many pathogenic bacteria can grow rapidly, increasing the risk of contamination or infection.
2. Identify the goal: to avoid the temperature danger zone to prevent bacterial growth and maintain sample integrity.
3. Evaluate each option by comparing it to the temperature danger zone: Refrigerating samples at 4°C keeps them below the danger zone, slowing bacterial growth.
4. Incubating cultures at 37°C is within the danger zone but is intentionally done to promote growth of specific microorganisms for study, so it is effective in that context.
5. Storing media in a freezer at -20°C keeps samples well below the danger zone, effectively preventing bacterial growth. Leaving samples at room temperature for extended periods keeps them within the danger zone, which is NOT an effective way to avoid it.