**Question:** The color code of plastic bag for disposing microbial laboratory culture waste –

A. Yellow
B. Blue
C. Green
D. Red

**Core Concept:** Color coding of plastic bags for segregating laboratory waste based on potential infectious risks.

**Why the Correct Answer is Right:** In microbiology laboratories, disposing microbial culture waste is crucial to prevent cross-contamination, occupational infection, and environmental risks. Plastic bags are used to segregate the waste based on the potential infectious risks they pose. The correct answer, **D. Red**, represents high-risk waste, which includes blood, body fluids, and infectious waste from cultures containing potentially pathogenic organisms. This helps in proper segregation, handling, and disposal of waste, ensuring safety for laboratory personnel and the environment.

**Why Each Wrong Option is Incorrect:**

A. **Yellow (Option A)**: Yellow is used for low-risk waste, such as contaminated equipment and disposable supplies. However, it does not accurately represent a specific category of infectious waste.

B. **Blue (Option B)**: Blue is used for non-infectious waste, like paper and cardboard. It does not directly represent a specific category of infectious waste.

C. **Green (Option C)**: Green is typically used for organic waste or biodegradable materials. It does not accurately represent a specific category of infectious waste.

**Clinical Pearl / High-Yield Fact:** Color coding of waste segregation in laboratories is essential for effective waste management, infection control, and environmental safety. It ensures proper handling and disposal of waste, preventing cross-contamination and infections. Always remember that **D. Red** represents high-risk infectious waste and should be segregated and disposed according to specific guidelines.