Why should you avoid packaging biological evidence in plastic or airtight containers?

• A. It makes the container too heavy
• B. It can cause moisture buildup promoting bacteria
• C. It damages the evidence physically
• D. It violates color-coding rules

Answer: (B)

Moisture control and microbial growth are the key ideas here. Plastic or airtight containers trap any moisture present on the item or from the surrounding environment, creating a humid microenvironment. That humidity fosters bacteria and fungi to multiply, which can degrade biological traces, alter DNA, and compromise the integrity of the evidence. By using breathable packaging and allowing the item to dry before sealing, you reduce water activity and slow microbial growth, helping preserve the sample for analysis. The other factors—weight, potential physical damage, or color-coding rules—aren’t the main preservation concern in this scenario.