Date of Award

Spring 5-2020

Document Type

Honors Thesis

Degree Name

Bachelor of Science

Department

Chemistry

Advisor/Committee Chair

Marisia Fikiet, Ph.D.

Committee Member

Igor Lednev, Ph.D

Abstract

Body fluid traces are a common and a major form of evidence that can be found at a crime scene, as it is a good source of DNA. As such, it is vital that body fluid evidence is properly detected and identified. Issues with the current methods of identifying body fluids and the large backlog of evidence in most forensic labs call for more accurate on-scene (in situ) body fluid identification. Past research has demonstrated that Raman spectroscopy is an advantageous tool for accurately and quickly identifying body fluids, namely in the laboratory. Portable Raman instruments have been created to meet the need for performing this task at the crime scene. Specifically, a number of handheld Raman instruments are commercially available. Our laboratory has previously tested such instruments and found them not suitable for the analysis of trace evidence because of poor spatial resolution. BioTools instrumentation company has developed a first portable Raman microscope, which has a much higher spatial resolutions than handheld instruments. This project was focused on evaluating the capability of this instrument for the identification of biological stains. Specifically, we targeted determining the effects of this instrument’s spectral resolution on the analysis of body fluids. For comparison, the spectra of powder and cast film proteins were also collected. The performance of the portable instrument was compared with that of a desktop instrument. We found that the portable Raman microscope was capable of producing spectra of proteins and body fluids of a comparable quality to its desktop counterpart. Overall spectral features were largely similar that allowed for quick identification of body fluid spectra via visual comparison. These results indicated that the BioTools portable Raman microscope can potentially be used for analyzing biological evidence immediately at the scene of the crime and could improve the quality of forensic investigations.

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