Fluorescent dye-based detection of trace DNA on forensic tapelifts from worn shirts

Abstract

ABSTRACT There is a desire in the forensic science community for a robust tool for detecting trace DNA at the crime scene or on collected evidence. Recent research supports the fluorescent DNA-binding dye Diamond Dye (DD) as potentially effective for this purpose. However, additional research is required into the use of DD on trace DNA samples collected from mock evidence (e.g. clothing) to establish its practicality in an operational setting. Most importantly, any tool for detecting trace DNA must have no negative impact on downstream processes and must produce a reliable signal of presence/absence of DNA. Therefore, we aimed to determine whether DD staining of tapelifts taken from mock clothing exhibits impacts DNA yield and STR profiling success, and whether observed fluorescence on stained tapelifts corresponded with DNA yield. Using a paired sample approach of stained/unstained tapelifts from the same item, our results suggest that DD-stained tapelift samples generally recovered less DNA than unstained tapelifts, which resulted in poorer STR profiling success. Further, there was no association between the degree of fluorescence observed for stained tapelifts and DNA yield or STR profiling success. Taken together, these results suggest that DD staining may not be suitable for detecting trace DNA on tapelifts.