Defense Date
2024
Document Type
Directed Research Project
First Advisor
Dr. Susan Greenspoon
Second Advisor
Dr. William Eggleston
Third Advisor
Dr. Sarah Seashols-Williams
Fourth Advisor
Dr. Christopher Ehrhardt
Abstract
In forensic science DNA extraction and purification are crucial to DNA analysis as evidentiary items vary in DNA quantity and quality. In casework the goal to is maximize DNA yield, remove PCR inhibitors, and develop a full profile while preserving evidence. Extraction methods are developed to target the DNA for optimal isolation. Solid-phase extraction is advantageous as it can extract DNA from a variety of tissue types, it is amenable to automation, and it provides quick and efficient purification of DNA. Solid-phase extraction methods may have complications with contaminants that hinder the quantity and quality of the DNA recovered. In this study, Nivea® body lotion and Silky® personal lubricant were identified as problematic to the extraction process and reduced DNA yields. The effects on DNA yield in various tissue samples were measured and approaches to mitigate these effects were investigated. The contaminants were found to cause DNA IQ™ resin clumping during the extraction and a significant decrease in DNA yield. Sodium dodecyl sulfate and reagent alcohol were tested at various concentrations to reduce the effects of the contaminants. Results showed that both 0.75% SDS and 20% alcohol used together in DNA IQ™ lysis buffer proved positive DNA yield effects in blood and saliva. The best results were seen when these additives were used in addition to increasing the suspension of DNA IQ™ resin added to the samples during the extraction of mock sexual assault samples.
Rights
© The Author(s)
Is Part Of
VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
4-30-2024