Porcine tissue samples shot with two different types of bullets, jacketed and nonjacketed, were collected in the fresh state and throughout moderate decomposition. Wound samples were microwave-digested and analyzed using inductively coupled plasma mass spectrometry (ICP-MS) to detect all elements present at measurable levels in gunshot residue (GSR). Elements detected included antimony (Sb), barium (Ba), and lead (Pb), which are considered characteristic of GSR, as well as iron (Fe) and copper (Cu). These five elements were used to differentiate shot tissue and unshot tissue, as well as tissue shot by the two different bullet types, both in the fresh state and throughout moderate decomposition. The concentrations of Cu, Sb, and Pb were able to distinguish the two bullet types in fresh tissue samples at the 95% confidence level. Cu and Pb were able to differentiate the bullet types throughout moderate decomposition at the 99% confidence level.

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According to an article in Science Matters, the newsletter of the Environmental Protection Agency, the average adult breathes in over 3,000 gallons of air every day. For this reason, having good air quality is extremely important. Many allergen particles are present in the atmosphere that interfere with this quality. When HVAC systems are installed to direct airflow through buildings, many of these particles are transferred indoors. To ensure air quality within buildings, tracking the flow patterns of these particles as the air is dispersed through heating and cooling systems is vital. One method to monitor this is through the creation of aerosolized particles with a DNA barcode (about 100 base pairs) that can be released and recaptured. Once released, the particles can be collected on filters of air filtration systems and analyzed using polymerase chain reaction (PCR). Because the PCR is performed on the eluent from a filter, it is of interest to know the DNA barcode recovery from a variety of filter types using a typical extraction medium. This project sought to quantify DNA extraction from three different types of aerosol filters: polyester felt, Teflon, and glass fiber, using 0.1% Triton X-100 in phosphate buffered saline (PBS) buffer as the elution buffer. Percent recoveries were calculated by comparison to no-filter controls. The DNA concentrations tested were 2