Social and Behavioral Sciences Commons^™

Performance Of A Dna And Protein Co-Extraction With Trypsin In Comparison To Two Proteinase K Based Dna Extraction Methods, Dinura A. Gunatilake

Student Theses

Effective DNA extraction methods are important for forensic applications. The main goal of this experiment was to determine if a newly developed trypsin based protein/DNA co-extraction method applied to contact traces would yield comparable results to a commercial Proteinase K method (QIAamp DNA Investigator Kit) and a Chelex extraction method with Tween 20 used in forensic laboratories. This was tested on 20 sets of sebaceous fingerprints on glass slides.

The results of this study demonstrate the trypsin co-extraction method yielded the highest amount of DNA. In the first comparison, the mean total DNA yields for the trypsin-co extraction method and …

An Exploration Of Protein And Dna Components In Fingerprint Residue, Ashley Borrego

Student Theses

The main focus of this project was to investigate the protein and DNA components in both sebaceous and eccrine fingerprints. This study investigated the relative content of DNA and proteins in eccrine fingerprints to sebaceous fingerprints. All volunteers were instructed to wash and dry their hands prior to depositing parallel thumbprints. Twenty volunteers were instructed to touch their face to produce sebaceous prints, and 5 volunteers were instructed to wear gloves over a heat source to produce sweaty or eccrine prints. Microscopy was used to score the cellular debris of the right fingerprint on a scale of 1-4 based on …

Identification Of Animal Species By Utilization Of Processed Remains, Melissa I. Gaud

Student Theses

An enzymatic method to process decomposed non-human bone for forensic DNA analysis is presented. Red snapper species is identified by sequencing of the COI gene.

Forensic analysis of DNA from non-human bones can be important in investigating a variety of forensic cases. However, decomposed bone is difficult to process for isolating DNA. In this study, a previously established enzymatic method was utilized to process bone samples that simulate decomposed specimens. Our results demonstrated that this enzymatic processing method is effective for removing decomposed soft tissues and outer surface materials such as mineralized bone connective tissue of bone fragment samples. Our …

Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes

Student Theses

DNA testing on touched objects is a valuable tool in forensic investigations, but DNA is usually present in low amounts, causing poor STR typing results. For touch DNA evidence, there is a clear need for additional individualization, especially for highly probative samples. This could be achieved by testing genetically variable proteins. The goal of this project was to develop a DNA/protein co-extraction method to facilitate DNA and protein testing on the same evidence item. Existing DNA extraction methods were carefully adjusted to allow for downstream mass spectrometry analysis. Initial experiments on saliva and fingerprints placed on glass suggested that trypsin …

Range Of Detection For Proteins And Dna From Fingerprints On Fired And Unfired Cartridge Casings, Stacey-Ann R. Sterling

Student Theses

Cartridges and spent cartridge casings can be probative pieces of evidence. Unfortunately due to a combination of factors such as exposure to high temperatures and initially low amounts of biological material on the surface, DNA testing so far has been mostly unsuccessful for these items. Typing other marker systems, such as protein polymorphisms, on the same biological evidence would add power of discrimination. To explore this option we developed a DNA-protein trypsin-based co-extraction method that was optimized for unfired and fired cartridges. Various sample wet and dry collection methods and multiple metal casings, such as aluminum, nickel, steel, and brass …