What is the purpose of reporting a degradation index and how does it influence downstream testing?

What is the purpose of reporting a degradation index and how does it influence downstream testing?

• A. Indicates sample quality; informs likelihood of successful amplification and choice of targets (short vs long)
• B. Determines donor identity with high certainty
• C. Measures the age of the sample
• D. Indicates contamination level only

Answer: (A)

Degradation index quantifies DNA integrity and serves as a practical gauge of sample quality. By comparing amplification of longer fragments to shorter ones, it reveals how degraded the DNA is. This directly informs how likely PCR amplification will be successful and what targets to pursue: degraded samples tend to amplify better when short or mini-amplicons are used, so downstream testing can be designed to maximize recoverable data. The index also helps anticipate allele drop-out and shapes interpretation thresholds for the final profile. It isn’t about identifying a donor, determining age, or measuring contamination level alone, which is why this option best fits the purpose: it ties DNA quality to the strategy and interpretation of subsequent tests.

Degradation index quantifies DNA integrity and serves as a practical gauge of sample quality. By comparing amplification of longer fragments to shorter ones, it reveals how degraded the DNA is. This directly informs how likely PCR amplification will be successful and what targets to pursue: degraded samples tend to amplify better when short or mini-amplicons are used, so downstream testing can be designed to maximize recoverable data. The index also helps anticipate allele drop-out and shapes interpretation thresholds for the final profile.

It isn’t about identifying a donor, determining age, or measuring contamination level alone, which is why this option best fits the purpose: it ties DNA quality to the strategy and interpretation of subsequent tests.