Effect of UV exposure on DNA deposited on drug capsules.

Illicit drugs are often made in less-than-sterile environments and can be stored in ways which can be detrimental to any DNA present, such as whether they are exposed to UV radiation. Previously, analysis of how exposure to UV impacted DNA for forensic applications has been in controlled laboratory conditions isolating a single component of UV radiation and often on DNA-rich samples such as bloodstains or saliva. To evaluate DNA persistence in more realistic conditions, capsules, such as those used to distribute controlled substances, were manually made and then packed into ziplock bags.

Illicit drug distribution: Evaluation of DNA transfer between ziplock bags and capsules.

Powders containing illicit substances are frequently poured into capsules and then distributed in small bags to users, often via intermediaries. We report on the transfer of DNA between individuals involved in making, packing, and transporting capsules within ziplock bags (ZLB) via two pathways, each using 10 ZLBs. A two-person chain was created where participant A made and packed the capsules into ZLBs and participant C then carried the bags for four days.

Shedding more light on shedders.

We report on testing 100 individuals for their shedder status with the aim of demonstrating whether the process of cell staining is reproducible when testing a large number of people. A previous report using the same method was based on 11 donors and indicated that there may be a continuum of shedder types within this small sample set. In this report we also expand the time points post-handwashing to 0, 15, 30, 60, and 180 min.

Cell counting to monitor swab efficiency.

Plastic bags, such as ziplock bags, have been used to transport illicit materials worldwide; however, very few studies have tried to optimize the recovery of DNA from these items. This study reports on the best combination of swabs and moistening solution for the greatest recovery of cellular material from ziplock bags. Five swabs, two different variations of Copan Diagnostics nylon 4N6FLOQSwabs, one Medical Wire rayon DRYSWAB, one IsoHelix rayon swab, and one Livingstone cotton swab, were evaluated with two moistening solutions, Triton X-100 in either distilled water or isopropanol.

Persistence of cellular material after exposure to water.

Disposing of items of forensic relevance in bodies of water is one countermeasure offenders can use to avoid detection. The impact of immersion in water has been explored for blood, saliva, and semen; however, few studies have assessed touch DNA. Here we report on the effect of exposure to water on the persistence of touch DNA over prolonged periods of time.