Forensic DNA analysis is one of the newest and most influential types of scientific evidence that is used in criminal investigations. Trace DNA samples can be collected at the crime scene by swabbing various surfaces that are commonly touched and can be compared to known samples collected from suspects. Once DNA samples are collected, they must be incubated before being extracted, quantified, and analyzed. The most common procedure for crime labs is to incubate DNA samples overnight, for approximately 12 hours. However, currently little to no research exists which can correlate the incubation time to DNA quantity. The ability to use shorter incubation times while observing similar DNA quantities could prove useful in time-sensitive cases and could improve lab efficiency.

In this study we used trace DNA swab samples from different surfaces to determine the effect of varying incubation times on the quantity of genetic material extracted. We collected our trace samples by swabbing ten different items in each of our four surface categories: cell phones, door handles, steering wheels, and the inside of rubber gloves. One swab from each sample was incubated at each of the three times: 2 hours, 4 hours, and overnight. There was a total of 120 trace samples which were then extracted and quantified. The quantified data was then analyzed to determine the relationship between incubation times and DNA quantity.

Victoria and Erin would like to thank Erik Hall for giving them the opportunity to complete this research and helping them throughout their time at SLU.