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Full-Text Articles in Life Sciences

Extraction Of Challenging Forensic Samples Using The Microgem Dna Extraction Kit, Falyn R. Vega Jun 2023

Extraction Of Challenging Forensic Samples Using The Microgem Dna Extraction Kit, Falyn R. Vega

Student Theses

In forensic science, DNA extraction can be a tedious and resource-intensive process. Extraction with Proteinase K is an industry standard but has its drawbacks, such as requiring multiple ionic detergents and washing steps. MicroGEM has developed a new enzyme called forensicGEM that is temperature-dependent and compatible with mesophilic enzymes, offering complete DNA extraction in about 20 minutes in a single tube, limiting contamination, loss of sample, and working time. ForensicGEM can extract DNA from highly degraded samples, potentially leading to more complete STR profiles. Highly degraded tissue and bone samples were collected and extracted with the forensicGEM …


Biological Factors Affecting Dna Shedding Propensity, Ines G. Cedillo-Cruz Jun 2022

Biological Factors Affecting Dna Shedding Propensity, Ines G. Cedillo-Cruz

Student Theses

Recovery of trace DNA is important in forensic casework because it is the main type of biological evidence found in both violent and non-violent crimes. Researchers have been trying to determine if there are individual differences in shedding propensity, or how much DNA an individual leaves behind. A model for determining this would benefit evidence interpretation if passive transfer scenarios are being considered, as it can affect the probative value of DNA evidence. This study compared the amount of DNA collected with adhesive D-Squame tape disks from the fingers of individual’s washed non-dominant and dominant hands after 30 minutes of …


Evaluating A Test For Shedding Propensity Using Tape Lifts From Different Skin Locations, Xiao M. Chen Dec 2021

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 …


Further Evaluation Of A Dry Vacuuming Technique For Recovery Of Dna From Handwritten Documents, Christian Hopkins Aug 2020

Further Evaluation Of A Dry Vacuuming Technique For Recovery Of Dna From Handwritten Documents, Christian Hopkins

Student Theses

A previously developed, non-destructive, homemade vacuum method for collecting biological material from handwritten documents had promising DNA results for white copy paper, preserved indented writing, and latent prints. Prior to casework implementation, additional validation experiments are warranted and here the method was tested for different paper substrates. This work describes testing of notebook paper, bank deposit slips, magazine pages, and manila envelopes. The quantity of recovered DNA varied from donor to donor, but the mean quantities showed a trend that can be explained by the different sizes and surface properties of the tested paper types. The rougher paper type, like …


Development Of Multiplex Pcr Assay As A Basis For Predicting Pigment Related Features, Stephanie A. Rodriguez Nov 2019

Development Of Multiplex Pcr Assay As A Basis For Predicting Pigment Related Features, Stephanie A. Rodriguez

Student Theses

Currently, short tandem repeats are used in forensic DNA typing to identify the DNA profiles recovered from evidence samples and deceased individuals. Recently, SNPs that are related to pigmentation have been researched for their use in the identification of phenotypic traits. The development of a SNP panel that could successful identify the eye and skin color of an individual, would be immensely useful in missing person cases or mass disaster victim identification. Eight SNPs were selected into a SNaPshot assay that could accurately predict eye and skin color, five for eye color and six for skin color. Development of the …


Investigating The Effects Of Trans-Spinal Direct Current Stimulation On The Expression Of Nkcc1 In Mice, Pasindu Weliwaththage May 2018

Investigating The Effects Of Trans-Spinal Direct Current Stimulation On The Expression Of Nkcc1 In Mice, Pasindu Weliwaththage

Student Theses

Trans-spinal direct current stimulation (tsDCS) is a non-invasive powerful tool demonstrated to positively affect behavior and motor function. tsDCS is a neuromodulatory technique capable of altering spinal and cortical excitability and even regain motor function after complete motor paralysis (Cortes et at, 2017). tsDCS causes immediate and long-term effects in spinal excitability (Ahmed, 2011, 2013; Ahmed and Wieraszko, 2012; Cogiamanian et al., 2011, 2012). Studies have been conducted on both healthy and injured subjects. The ultimate goal is to ameliorate the devastating effects of Spinal Cord Injury. Though researchers have been successful in improving motor function, the molecular basis of …


The Y-Screen Assay: Validation And Evaluation Of Subsequent Str Success, Kassandra Luyando May 2018

The Y-Screen Assay: Validation And Evaluation Of Subsequent Str Success, Kassandra Luyando

Student Theses

There are hundreds of untested sexual assault kits in police custody. As of 2017, New York State passed a law stating that all untested kits must be turned over to forensic laboratories to be tested, causing backlogs at laboratories to increase. The Y-Screen assay is a DNA extraction protocol which utilizes NaOH to rapidly lyse epithelial and sperm cells, and the Quantifiler Trio DNA quantification kit to detect the presence or absence of male DNA prior to standard sample processing. The Y-Screen assay is a commercial product used in this research to test a defined set of validation samples with …


Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes Aug 2017

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 …


The Effect Of Resource Quality And Species Interactions On The Colonization Behavior Of The Black Blow Fly, Phormia Regina (Meigen), Melissa N. Branker May 2017

The Effect Of Resource Quality And Species Interactions On The Colonization Behavior Of The Black Blow Fly, Phormia Regina (Meigen), Melissa N. Branker

Student Theses

During decomposition, there are many different insects groups that utilize carrion as a resource. In particular, blow flies (Order: Diptera; Family: Calliphoridae) are considered to be a forensically important family due to their ability to rapidly locate and colonize a carrion resource. As a result, blow flies are commonly used as indicator species in PMI estimations. However, recent research indicates that the colonization behavior of these species can be influenced by a variety of abiotic and biotic factors. In this study, the effects of arrival order, resource quality and bacterial or species cues on the oviposition behavior of Phormia regina …