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Social and Behavioral Sciences Commons™
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Full-Text Articles in Social and Behavioral Sciences
Evaluating A Test For Shedding Propensity Using Tape Lifts From Different Skin Locations, Xiao M. Chen
Evaluating A Test For Shedding Propensity Using Tape Lifts From Different Skin Locations, Xiao M. Chen
Student Theses
The shedding propensity of a person can assist data interpretation in casework when assessing the possibility of passive transfer for DNA analysis. Past studies on shedding propensity evaluated palmar skin (washed and unwashed) deposits. This study compared different skin locations with respect to shedding propensity, and explored the potential of tape-lifts as a skin surface collection method. Eight different skin types and samples were collected with adhesive tape disks from 28 participants over three non-consecutive days; the washed and unwashed fingers from both hands, toe, and arm, neck below ear, and nape. Samples were extracted, quantified, amplified, genotyped, and evaluated …
Determination Of Human Shedding Propensity Based On Str Results, Genevieve Trapani
Determination Of Human Shedding Propensity Based On Str Results, Genevieve Trapani
Student Theses
Trace DNA evidence may be discovered at a crime scene after having been deposited by a person of interest via active or passive transfer. Based on previous studies, passive transfer of one’s DNA is influenced by their shedding propensity, or probability of depositing a detectable amount of DNA through touch. Determining the shedding propensity of a person of interest can aid in trace DNA interpretation in forensic casework. This study explored STR profile quality and the presence of a DNA mixture for different skin surface locations, including fingertips before and after handwashing. As expected, unwashed fingers showed a higher prevalence …
Discrimination Of Monozygotic Twins Using Dna Methylation Levels Of One Cpg Site At Chromosome 3, Dino O. Robinson
Discrimination Of Monozygotic Twins Using Dna Methylation Levels Of One Cpg Site At Chromosome 3, Dino O. Robinson
Student Theses
Conventional STR typing, commonly used in forensics for human identification, poses a problem in criminal cases and paternity disputes involving monozygotic (MZ) twins because they share identical DNA sequences. To date, no routine method is available in forensics to differentiate between individuals of MZ pairs. Recently, epigenetic methods measuring differential DNA methylation patterns have been applied to MZ twin differentiation. In this study, we investigated the potential to identify MZ twins using a previously identified DNA methylation site in chromosome 3, cg18562578, in a sample of 129 MZ and 37 dizygotic (DZ) twin pairs. We used bisulfite converted saliva DNA …
Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes
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 …