Which statement about the sensitivity of forensic protocols is correct?

Which statement about the sensitivity of forensic protocols is correct?

• A. 1 microgram
• B. Sensitivity can reach as low as 125 picograms.
• C. 125 nanograms
• D. 1 picogram

Answer: (B)

Sensitivity in forensic protocols refers to the smallest amount of DNA that can still yield a usable profile after amplification. For many standard forensic STR systems, the practical lower limit is around 125 picograms per reaction. That amount corresponds to roughly a few dozen copies of the genome (about 18–19 diploid genome equivalents), which can still produce a partial but informative profile, though stochastic effects may cause incomplete or biased results. Therefore, stating that sensitivity can reach as low as 125 picograms reflects the typical capability of common protocols. The other amounts aren’t describing this limit: a microgram is far more DNA than needed and doesn’t define sensitivity; 125 nanograms is about a thousand times higher than 125 picograms and isn’t the lower detection threshold; 1 picogram is well below what standard kits reliably amplify and wouldn’t represent the practical sensitivity.

Sensitivity in forensic protocols refers to the smallest amount of DNA that can still yield a usable profile after amplification. For many standard forensic STR systems, the practical lower limit is around 125 picograms per reaction. That amount corresponds to roughly a few dozen copies of the genome (about 18–19 diploid genome equivalents), which can still produce a partial but informative profile, though stochastic effects may cause incomplete or biased results. Therefore, stating that sensitivity can reach as low as 125 picograms reflects the typical capability of common protocols. The other amounts aren’t describing this limit: a microgram is far more DNA than needed and doesn’t define sensitivity; 125 nanograms is about a thousand times higher than 125 picograms and isn’t the lower detection threshold; 1 picogram is well below what standard kits reliably amplify and wouldn’t represent the practical sensitivity.