Using resolution calculations to assess changes in capillary electrophoresis run parameters

Capillary electrophoresis is widely used in the forensic community for the analysis of Short Tandem Repeat DNA. The CE system used in most forensic laboratories allows the user to modify standard operational protocols to accommodate some samples that fall outside of interpretational guidelines. We have made operational changes and monitored system resolution and the ability of the software to identify alleles as a result of these modifications. Increased amount of amplified product in the injection preparation, lengthened injection times or repeated injections of the same sample were all investigated along with variations in run voltages. Certain protocol modifications offer some advantages to the analysis of STRs and may allow the analyst to avoid extraction of additional portions of crime scene samples to achieve interpretable results.