Forensic utility of carbon isotope ratio variations in PVC tape backings.

Forensic interest in adhesive tapes with polyvinyl chloride (PVC) backings (electrical tape) derives from their use in a variety of illicit activities. Due to the range of physical characteristics, chemical compositions, and homogeneity within a single roll of tape, traditional microscopic and chemical analyses can offer a high degree of discrimination between tapes, permitting the assessment of potential associations between evidentiary tape samples. The carbon isotope ratios of tapes could provide additional discrimination among tape samples.

Forensic utility of isotope ratio analysis of the explosive urea nitrate and its precursors.

Urea nitrate (UN) is an improvised explosive made from readily available materials. The carbon and nitrogen isotope composition of UN and its component ions, urea and nitrate, could aid in a forensic investigation. A method was developed to separate UN into its component ions for δ(15)N measurements by dissolving the sample with KOH, drying the sample, followed by removal of the urea by dissolution into 100% methanol.

Evaluation of commercial RNA extraction kits for the isolation of viral MS2 RNA from soil.

Nucleic acid extraction is a critical step in the detection of an unknown biological agent. However, success can vary depending on the isolation and identification methods chosen and the difficulty of extraction from environmental matrices. In this work, bacteriophage MS2 RNA was extracted from three soil matrices, sand, clay, and loam, using five commercially available kits: the PowerSoil Total RNA Isolation, E.