Date of this Version
2024
Document Type
Poster
Abstract
The presence of metallic ions has been established to inhibit DNA Taq Polymerase, a key component for the Polymerase Chain Reaction (PCR), making amplification challenging when trying to generate a DNA profile of bullet handler transferred DNA, commonly called touch DNA from the unfired bullet casing surface. The goal of this research is to determine the amount of various bivalent cations such as Copper (Cu+2) and Zinc (Zn+2), which are suspected PCR amplification reaction inhibitors. A known concentration (0.1ng/µL) of liquid standardized human DNA, the total amount (1 ng, 3 ng, and 5 ng) was deposited at outlined locations onto the unfired brass ammunition, and the samples were air dried in the clean hood. The deposited DNA was lifted by sterile cotton double swabbing technique, using two (2) different solutions such as Rapid Stain Identification (RSID) kit universal buffer, TE dilution buffer, or deionized water. To determine the quantity (percentage) of various metallic ions recovered from swabbing, the Electron Micro Probe Analyzer (EPMA) technique was utilized to quantify (percentage) various bivalent cations collected from the swabbed samples. Each of the swab samples recovered more Cu+2 ions than Zn+2 ions, though the ratios were variable between solutions. Deionized water was shown to recover more bivalent cations than any other tested solution. Deionized water recovered 6 times more bivalent cations than RSID buffer and 1.6 times more than TE dilution buffer.
DOI
https://doi.org/10.25148/gfjcsr.2024.3
Recommended Citation
Bliss, Desiree; Troyer, AJ; Lodhi, Khalid; Luo, Zhiping; Balabhadra, Sangeetha; and Prisaznik, Emily, "Qualification of Metallic Ions Recovered from Swabbing Unfired Brass Bullet Casings" (2024). Global Forensic and Justice Center Symposium Research. 3.
https://digitalcommons.fiu.edu/gfjcsr/3