Why is a cold chain maintained for biological evidence?

Why is a cold chain maintained for biological evidence?

• A. To speed up degradation
• B. To preserve biological samples by slowing degradation and microbial growth
• C. To label samples
• D. To disinfect the samples

Answer: (B)

Keeping biological evidence cold slows down enzymatic activity, chemical reactions, and microbial growth. This helps preserve the sample’s original condition, including DNA, proteins, and overall composition, so analyses later on are accurate and reliable. Temperature control also minimizes changes from transport and handling, such as damage from temperature swings or repeated freeze–thaw cycles. Growing or accelerating degradation would destroy information; labeling is a separate handling step, not a reason to maintain a cold chain; and disinfection is done through cleaning agents, not by simply chilling the sample.

Keeping biological evidence cold slows down enzymatic activity, chemical reactions, and microbial growth. This helps preserve the sample’s original condition, including DNA, proteins, and overall composition, so analyses later on are accurate and reliable. Temperature control also minimizes changes from transport and handling, such as damage from temperature swings or repeated freeze–thaw cycles.

Growing or accelerating degradation would destroy information; labeling is a separate handling step, not a reason to maintain a cold chain; and disinfection is done through cleaning agents, not by simply chilling the sample.