Date of Award

Spring 2019

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

School

Criminal Justice, Forensic Science, and Security

Committee Chair

Dr. Kuppareddi Balamurugan

Committee Chair School

Criminal Justice, Forensic Science, and Security

Committee Member 2

Dr. Philip Carlan

Committee Member 2 School

Criminal Justice, Forensic Science, and Security

Committee Member 3

Dr. Dean Bertram

Committee Member 3 School

Criminal Justice, Forensic Science, and Security

Abstract

The identification of bodily fluids and tissues is often applied to criminal investigations to clarify events that may or may not have taken place. Current forensic techniques can identify blood, saliva, seminal fluid, and spermatozoa, but there is a clear absence of reliable testing to identify vaginal epithelial tissue. Though there are serological tests available for this purpose, tissue-specific methylation markers have recently been investigated as a candidate for the identification of blood, saliva, and spermatozoa.

In this study, tissue-specific methylation markers were analyzed to identify a set of markers for the differentiation of vaginal fluid from blood, saliva, and semen. From the four tissue types collected, genomic DNA was extracted, quantitated, and bisulfite-modified to preserve the methylation information. Candidate markers were amplified then pyrosequenced to determine the percent methylation of specific CpG sites. The level of significance between tissues was determined using one way ANOVA Tukey’s posthoc test by SPSS statistical package.

Three markers, cg4739647, cg6266993, and cg9323727 were found to be hypermethylated in vaginal fluid compared to blood, saliva, and semen. The differences between methylation levels at nearly all analyzed CpG sites were found to be significant, suggesting that these markers may be used to identify vaginal epithelial tissue for forensic purposes. Pyrosequencing has several advantages over conventional serological analysis, and the development of a multiplex kit using these markers will aid in the conservation of precious DNA samples that can be used for other forensic purposes.

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