What needs to be clarified
Assess inhibition-control evidence and whether validated dilution or cleanup could clarify the weak signal.
Materials to prepare
- Retained extract and original trace residue
- Quantitative PCR curves including internal and negative controls
- Extraction record and assay validation criteria
What to compare
Compare control delay, blanks and input volumes with assay criteria. Where material permits, compare untreated extract with validated dilution or cleanup. Account for DNA loss on dilution and different inhibitor sensitivity in quantification and STR assays.
Possible outcome of the analysis
A quality assessment may explain preparation choices and whether resulting data support further interpretation, including conditions that restrict the answer.
Limits of the conclusions
An inhibition control identifies no donor and guarantees no profile. Absence of a signal does not establish absence of contact; dilution may increase stochastic effects.