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Full-Text Articles in Forensic Science and Technology

Understandings Of Vulnerability And Social Determinants Of Health In Forensic And Expert Social Anthropology: A Scoping Review, James W. W. Rose, David M. Tran Apr 2024

Understandings Of Vulnerability And Social Determinants Of Health In Forensic And Expert Social Anthropology: A Scoping Review, James W. W. Rose, David M. Tran

The Qualitative Report

Forensic and expert social anthropology (FESA) is a branch of social anthropology that specialises in the provision of evidence to legal-administrative processes, which are overseen by courts and other legally empowered bodies, and which give regard to the social cultures of legally and administratively involved individuals and communities (LAIICs). Despite a preoccupation with political advocacy in the broader philosophy of social anthropology, FESA literature does not typically give regard to LAIIC vulnerability defined qualitatively in terms of social determinants of health, including physical, mental, and social well-being. This paper presents findings from a JBI/PRISMA-ScR scoping review of n=1,674 texts, identifying …


Quality Management And Oversight Of Texas Forensic Science Service Providers, Sarah P. Chu Sep 2023

Quality Management And Oversight Of Texas Forensic Science Service Providers, Sarah P. Chu

Dissertations, Theses, and Capstone Projects

Forensic science oversight in the U.S. largely relies upon voluntary third-party forensic laboratory accreditation programs. Without a national system of regulation and given the highly fragmented local systems of control, few forensic science service providers (FSSPs) are subject to regulatory oversight beyond their third-party accreditors. Texas is unique in its establishment of a robust statewide oversight system and a strong governmental culture of transparency, permitting this study of forensic quality management. This study consisted of two parts. The first part of this dissertation characterized and analyzed quality incident reports (QIRs) published by the Texas Department of Public Safety Crime Laboratory …


Examining The Relationship Between Legal Systems And Forensic Science: Current Issues And Proposed Solutions, Rowan Dunton May 2023

Examining The Relationship Between Legal Systems And Forensic Science: Current Issues And Proposed Solutions, Rowan Dunton

Themis: Research Journal of Justice Studies and Forensic Science

Forensics and legal systems are often seen working together, but the relationship between the two disciplines is thornier and more complex than it may appear on the surface. This paper will examine why courtrooms struggle to accommodate forensic fields, how the nature of science can impede its utilization in court, and where legal education may fall short in educating students about the forensic sciences. After the literature is reviewed, solutions will be proposed to address each area of concern. Where possible, these solutions expand on existing infrastructure and ideas to make them easier to incorporate. Since the greater-scope issue is …


The Crisis Of Femicides In Mexico, Alejandra Vela May 2023

The Crisis Of Femicides In Mexico, Alejandra Vela

Themis: Research Journal of Justice Studies and Forensic Science

Femicides are a growing issue in Mexico. These murders are intertwined with the incompetence of authorities, poverty, corruption, and organized crime. Authorities tend to blame victims by not taking missing reports seriously, nor do they conduct searches in these urgent situations. Authorities do not have DNA databases, space in morgues, and have little forensic science training. Ways of identifying remains involve odontology, bitemarks, and saliva. These provide a means of identifying through individual characteristics and DNA. Evidence is usually mishandled and not tested, or purposely lost to stop the investigation, thus, involving corruption. Criminal organizations, known as cartels, bribe authorities …


Dna Transfer And Persistence On Non-Porous Surfaces Submerged In Spring Water [Preliminary Study], Morgan L.. Korzik, Josep De Alcaraz-Fossoul, Michael S. Adamowicz, David San Pietro Jan 2023

Dna Transfer And Persistence On Non-Porous Surfaces Submerged In Spring Water [Preliminary Study], Morgan L.. Korzik, Josep De Alcaraz-Fossoul, Michael S. Adamowicz, David San Pietro

Forensic Science: Faculty and Staff Publications

Submerged items are often thought to lack evidentiary value. However, previous studies have shown the ability to recover DNA from submerged porous items for upwards of six weeks. The crevices or interweaving fibers in porous items are thought to protect DNA from being washed away. It is hypothesized that, because non-porous surfaces do not have the same traits that might aid in DNA retention, then DNA quantities and the number of donor alleles recovered would decrease over longer submersion periods. Additionally, it is hypothesized that DNA quantity and the number of alleles would be negatively affected by flow conditions. Neat …


Evaluation Of Direct-To-Amplification Cell Lysis Techniques For Forensically Relevant Non-Sperm Cells, Rhea Arya Jan 2023

Evaluation Of Direct-To-Amplification Cell Lysis Techniques For Forensically Relevant Non-Sperm Cells, Rhea Arya

Master of Science in Forensic Science Directed Research Projects

While efforts have been made to reduce the pervasive backlog of sexual assault evidence collection kits, the actual laboratory process remains very time-consuming due to the requirement of a differential lysis step before DNA purification, as well as intricate mixture analysis towards the end of the DNA workflow. Previous work in the Dawson Green laboratory at VCU has developed alternative solutions for differential extractions with sexual assault samples using both an in-tube and microdevice assay. Prior work led to the identification of an alternative sperm lysis method – alkaline lysis using 1M NaOH. However, the current lysis method used for …


Development And Validation Of Microrna Markers For Forensic Body Fluid Identification Using Rt-Qpcr, Jane Goble Jan 2023

Development And Validation Of Microrna Markers For Forensic Body Fluid Identification Using Rt-Qpcr, Jane Goble

Master of Science in Forensic Science Directed Research Projects

Body fluid identification is one of the first and most fundamental steps in the forensic DNA workflow. It allows analysts to determine where a sample might exist on an item of evidence, as well as the type of sample that they are dealing with. However, current serological methods have been documented to produce false or inaccurate results in some cases, and may consume large amounts of sample during processing. Molecular methods, such as the use of microRNA and microbial profiles have been introduced as a means to increase specificity of testing, and have even been combined into a singular assay …


A Comparison Of Methods Used For The Elimination Of Organics From Soil Prior To Analysis By Ftir-Atr And Sem-Eds, Argeliz Pomales Aug 2022

A Comparison Of Methods Used For The Elimination Of Organics From Soil Prior To Analysis By Ftir-Atr And Sem-Eds, Argeliz Pomales

Student Theses

This project suggests improvements to the treatment methods utilized for the sample preparation and evaluation of minerals in soil samples encountered in forensic science casework and research. The evaluation of pre-treated and post-treated soil samples were performed using Fourier-Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR) and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). Because soil samples contain a significant amount of organic matter and water which interfere with examination of these minerals while using these instruments, pretreatment methods are necessary to isolate the mineral fraction for examination and analysis.

Soil samples were first sieved with various size stainless steel mesh …


Cognitive And Other Types Of Biases Affecting Forensic Evidence: Research Analysis And Expert Conclusions, Sukhmanpreet Kaur Jan 2022

Cognitive And Other Types Of Biases Affecting Forensic Evidence: Research Analysis And Expert Conclusions, Sukhmanpreet Kaur

Themis: Research Journal of Justice Studies and Forensic Science

This paper identifies the issue of cognitive bias, with emphasis on confirmation bias, and its implications within the forensic science field. Biased thinking or processing of forensic evidence can have significant effects on an investigation process. The literature analyzed discusses the consequences of providing contextual or irrelevant ancillary information to forensic experts. Following this discussion, the opinions held by forensic professionals with regards to confirmation bias and erroneous conclusions will likewise be evaluated. It is important that the forensic science field continues to listen to its experts in order to develop solutions for dealing with and preventing instances of confirmation …


Impact Of 1,4-Dithiothreitol (Dtt) On Microbial Community Structures Associated With Human Semen Samples, Christian R. Blaise Jan 2022

Impact Of 1,4-Dithiothreitol (Dtt) On Microbial Community Structures Associated With Human Semen Samples, Christian R. Blaise

Master of Science in Forensic Science Directed Research Projects

Body fluid identification (BFID) is one of the most important steps in forensic science as it provides important context to how DNA analysis should be performed on biological samples found at the scene of a crime. Many scientific methods on BFID have been developed over the years with respective benefits and flaws. One emerging method in recent years is microbial signature based BFID. This method uses the same DNA extract that is utilized for human DNA profile generation for microbial analysis. Although DNA is extracted from all body fluid samples without any additional steps, extraction of human DNA from semen …


Optimization And Comparison Of Methods For Separation Of Spermatozoa From Superabsorbent Polymer-Containing Forensic Evidence, Hannah Wells Jan 2022

Optimization And Comparison Of Methods For Separation Of Spermatozoa From Superabsorbent Polymer-Containing Forensic Evidence, Hannah Wells

Master of Science in Forensic Science Directed Research Projects

Sexual assault is currently one of the most prevalent crimes that affects victims of all ages. Forensic DNA analysts often confirm proof of contact in sexual assault cases through the identification of spermatozoa and subsequent STR profiling. Diapers and other feminine hygiene products, such as maxi pads and ultrathin pads, are types of superabsorbent polymer-containing evidence that complicate the process of DNA analysis due to the trapping of the spermatozoa in the gel-like matrix. In this study, a comparison of methods was performed to determine which extraction technique produces the highest sperm cell and DNA yield and generates a usable …


Development Of A Loop-Mediated Isothermal Amplification (Lamp) Assay For Detection Of Mirnas, Alisha B. Whelan Jan 2022

Development Of A Loop-Mediated Isothermal Amplification (Lamp) Assay For Detection Of Mirnas, Alisha B. Whelan

Master of Science in Forensic Science Directed Research Projects

Body fluid identification serves a vital role in contextualizing biological evidence received in forensic laboratories. While several fluids can be presumptively detected using immunological or catalytic tests, these tests are susceptible to false results and have limited sensitivity. True confirmatory testing is still somewhat limited in forensic laboratories. With the advancement of DNA typing technologies, laboratories can develop DNA profiles from trace amounts of sample, increasing the demand for sensitive and accurate body fluid detection. This project proposes using loop-mediated isothermal amplification (LAMP) as a method to rapidly detect microRNAs (miRNAs) that are differentially expressed in various body fluids with …


Stability And Variation Within Donors Of Mirna Markers For Body Fluid Identification, Kelsey R. Price Jan 2022

Stability And Variation Within Donors Of Mirna Markers For Body Fluid Identification, Kelsey R. Price

Master of Science in Forensic Science Directed Research Projects

Traditional enzymatic tests for body fluid identification are prone to false negatives, false positives, and several body fluids do not have confirmatory or reliable presumptive tests. Therefore, molecular-based tests may be more reliable, such as messenger RNA (mRNA), microbial DNA, or microRNA (miRNA) assays.

miRNAs are small, noncoding RNAs whose main function in-vivo is the regulation of protein expression by selectively suppressing the translation of their corresponding mRNAs. They also lack a poly-A tail, and because of this, their small size, and their association with other molecules such as the RISC protein complex, they are more robust than other RNAs, …


A Quantifiler Trio-Based Hrm Mixture Screening Assay For The Quantstudio 6 Flex Qpcr Platform, Dayanara A. Torres Jan 2022

A Quantifiler Trio-Based Hrm Mixture Screening Assay For The Quantstudio 6 Flex Qpcr Platform, Dayanara A. Torres

Master of Science in Forensic Science Directed Research Projects

At present, the forensic DNA workflow is not capable of providing information about the contributor status (single source vs. mixtures) of evidentiary samples prior to end-point analysis. This shortcoming can exacerbate the challenges inherent to mixtures and low-template DNA samples. Provided additional sample information earlier in the workflow, protocols could be implemented to mitigate these challenges. High-resolution melt (HRM) curve analysis is a technique used to detect genetic variation in DNA fragments and in the last decade has been evaluated for use in differentiation of samples by genotype and/or contributor status. To this end, a proof-of-concept HRM assay using the …


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 …


The Understanding Of Digital And Multimedia Evidence (Dme) By Attorneys And Digital Forensic Examiners (Dfe) Within The United States Criminal Justice System, Joseph Levi White Dec 2021

The Understanding Of Digital And Multimedia Evidence (Dme) By Attorneys And Digital Forensic Examiners (Dfe) Within The United States Criminal Justice System, Joseph Levi White

Dissertations

One goal of this research was to determine potential themes that may influence the understanding of Digital and Multimedia Evidence (DME) by attorneys and Digital Forensic Examiners (DFE) within the United States Criminal Justice System. Qualitative semi-structured interviews were conducted to gather information from experienced criminal attorneys and DFEs regarding potential influences on their understanding of DME. The results of these interviews were transcribed, and the data coded to allow for qualitative analysis. Five themes were developed from this data and are thought to play a role in understanding of DME by attorneys and DFEs: motivation for involvement in the …


Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba Dec 2021

Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba

Student Scholar Symposium Abstracts and Posters

Forensic analysis of suspected narcotics is often dangerous as the substances’ composition is unknown. Many techniques for drug identification require handling of the substance outside of its packaging, which can expose the analyst to potentially harmful chemicals. The TruNarc Handheld Narcotics Analyzer is a portable Raman spectroscopy device that is non-destructive of evidence and can be used to screen drugs through simple packaging to minimize the risk of exposure. The Orange County Crime Lab (OCCL) is testing the limits of this device to determine if it can be used to screen new evidence within the Seized Drugs Lab. The OCCL …


Evaluation Of The Potential Of Automated Sem-Eds Analysis For The Discrimination Of Inorganic Soil Particles, Anna S. Duggar Sep 2021

Evaluation Of The Potential Of Automated Sem-Eds Analysis For The Discrimination Of Inorganic Soil Particles, Anna S. Duggar

Dissertations, Theses, and Capstone Projects

Soil, that complex mixture of minerals, organic particles, chemicals, and anthropogenic materials, is ubiquitous and easily transferred, which gives it forensic relevance. Forensic soil analysis has traditionally included the identification and comparison of both organic and inorganic components, the inorganic portion being most commonly examined by light microscopy and other instrumental techniques. Predominantly, the inorganic materials in soil are naturally-occurring minerals, contributed as grains from the surrounding bedrock, which gives a soil its regional character. That parent material then undergoes physical, chemical, and anthropogenic changes producing wide geographic variation within a single region. This variation forms the basis for potential …


The Absence Or Misuse Of Statistics In Forensic Science As A Contributor To Wrongful Convictions: From Pattern Matching To Medical Opinions About Child Abuse, Keith A. Findley Apr 2021

The Absence Or Misuse Of Statistics In Forensic Science As A Contributor To Wrongful Convictions: From Pattern Matching To Medical Opinions About Child Abuse, Keith A. Findley

Dickinson Law Review (2017-Present)

The new scrutiny that has been applied to the forensic sciences since the emergence of DNA profiling as the gold standard three decades ago has identified numerous concerns about the absence of a solid scientific footing for most disciplines. This article examines one of the lesser-considered problems that afflicts virtually all of the pattern-matching (or “individualization”) disciplines (largely apart from DNA), and even undermines the validity of other forensic disciplines like forensic pathology and medical determinations about child abuse, particularly Shaken Baby Syndrome/Abusive Head Trauma (SBS/AHT). That problem is the absence or misuse of statistics. This article begins by applying …


Powerplex® Fusion 6c System Versus Powerplex® Fusion 5c: A Comparison Of Performance Metrics, Caitlin M. Mccaughan Jan 2021

Powerplex® Fusion 6c System Versus Powerplex® Fusion 5c: A Comparison Of Performance Metrics, Caitlin M. Mccaughan

Theses and Dissertations

Following the FBI mandated expansion of the CODIS core loci from 13 to 20, several manufacturers developed short tandem repeat (STR) typing kits in response to the new criteria. One such manufacturer was the Promega Corporation, which released the PowerPlex® Fusion 5C megaplex STR typing kit (Fusion 5C) in 2012. Currently, the Virginia Department of Forensic Science (VDFS) utilizes this amplification kit for both casework and database applications. In 2015, Promega released the PowerPlex® Fusion 6C STR typing kit (Fusion 6C), which contains three additional loci beyond those included in PowerPlex® Fusion 5C, and a sixth color channel. The power …


Evaluation Of Cell Lysis Techniques For Direct Amplification Of Sexual Assault Samples, Sarah Schellhammer Jan 2021

Evaluation Of Cell Lysis Techniques For Direct Amplification Of Sexual Assault Samples, Sarah Schellhammer

Master of Science in Forensic Science Directed Research Projects

Sexual assault is one of the most common crimes committed today with a delay in sample processing, resulting in the “rape kit backlog”. The traditional method to extract DNA from these samples containing both male and female DNA is a differential extraction; taking hours to process. This study examined a variety of different cell lysis techniques to develop a method which can consistently generate high-quality profiles at a fast rate and with low volumes when compared to the currently used method in our laboratory.

Six lysis methods, in addition to the currently used forensicGEM™ Sperm kit, were performed on …


Powerplex® Fusion 6c System Versus Powerplex® Fusion 5c: A Comparison Of Performance Metrics, Caitlin M. Mccaughan Jan 2021

Powerplex® Fusion 6c System Versus Powerplex® Fusion 5c: A Comparison Of Performance Metrics, Caitlin M. Mccaughan

Master of Science in Forensic Science Directed Research Projects

Following the FBI mandated expansion of the CODIS core loci from 13 to 20, several manufacturers developed short tandem repeat (STR) typing kits in response to the new criteria. One such manufacturer was the Promega Corporation, which released the PowerPlex® Fusion 5C megaplex STR typing kit (Fusion 5C) in 2012. Currently, the Virginia Department of Forensic Science (VDFS) utilizes this amplification kit for both casework and database applications. In 2015, Promega released the PowerPlex® Fusion 6C STR typing kit (Fusion 6C), which contains three additional loci beyond those included in PowerPlex® Fusion 5C, and a sixth color channel. The power …


Creation And Optimization Of An Optical Trapping Microfluidic Device For The Separation Of Mock Forensic Sexual Assault Samples, Mackenzie Lally Jan 2021

Creation And Optimization Of An Optical Trapping Microfluidic Device For The Separation Of Mock Forensic Sexual Assault Samples, Mackenzie Lally

Master of Science in Forensic Science Directed Research Projects

Cell mixtures are often seen in forensic samples and commonly involve sexual assault cases where mixtures of sperm cells and vaginal epithelial cells are frequently encountered. This produces challenges in downstream analysis in the form of STR mixture profiles. The only method currently in use in crime laboratories for front-end sperm and epithelial cell separation is differential extraction. This method often results in STR mixture profiles due to carryover into both the male and female fractions and suffers from a wide range of efficiency depending on the laboratory or individual processing the sample. Optical trapping offers an alternative method for …


Evaluation Of Dna Extraction Efficiencies Of Promega’S Dna Iq™ Methods And Casework Extraction Kit For Low Template Samples, Emily M. Anderson Jan 2021

Evaluation Of Dna Extraction Efficiencies Of Promega’S Dna Iq™ Methods And Casework Extraction Kit For Low Template Samples, Emily M. Anderson

Master of Science in Forensic Science Directed Research Projects

Biological evidence from crime scene samples frequently contain low levels of DNA, such as the most predominant form of evidence, which is DNA deposited by handling objects or “touch evidence”. To maximize the DNA yield recovered from theses challenging samples, forensic laboratories must optimize the extraction methods utilized to isolate and purify DNA for downstream short tandem repeat (STR) amplifications. Currently, the Virginia Department of Forensic Science (VADFS) uses a DNA IQ™ System (DNA IQ) extraction method for isolation of DNA from most forensic samples. This extraction procedure, which combines DNA IQ™ lysis buffer and Dithiothreitol (DTT), has been validated …


Qualitative Analysis Of Luminol Efficacy On Bleach-Cleaned And Paint-Concealed Blood, Adam Wykoff May 2020

Qualitative Analysis Of Luminol Efficacy On Bleach-Cleaned And Paint-Concealed Blood, Adam Wykoff

Themis: Research Journal of Justice Studies and Forensic Science

The presence of blood at a crime scene can provide investigators with a treasure trove of information regarding the nature and circumstances of a particular crime and aid in crime scene reconstruction; however, attempts at concealing blood are common scenarios. The development of chemiluminescent and fluorescent-based presumptive tests, such as the luminol and fluorescein tests, have made it more challenging to definitively remove or mask blood on a surface. The purpose of this experiment was to qualitatively measure the overall efficacy of luminol, concerning its ability to positively detect small bloodstains found on common household floor surfaces (wood, carpet, and …


Validation Of Fast Spectrochemical Screening Methods For The Identification Of Counterfeit Pharmaceutical Packaging, Emily Ann Haase Jan 2020

Validation Of Fast Spectrochemical Screening Methods For The Identification Of Counterfeit Pharmaceutical Packaging, Emily Ann Haase

Graduate Theses, Dissertations, and Problem Reports

Counterfeit pharmaceuticals are an actively developing health and economic threat worldwide. Particularly prevalent are counterfeit pharmaceuticals distributed in emerging nations and through internet pharmacies or e-pharmacies. Although technology has been developed that discourages anti-counterfeiting practices (such as optically variable devices, invisible ink, and track-and-trace technology), it remains somewhat novel and expensive to implement on a widespread scale.

In this study, Laser Induced Breakdown Spectroscopy (LIBS) and Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) were proposed as fast and non-invasive tools for the identification of counterfeit pharmaceutical packages. The main objective of this research was to develop and evaluate the capabilities …


Statistical Evaluation Of Randomly Acquired Characteristics On Outsoles With Implications Regarding Chance Co-Occurrence And Spatial Randomness, Nicole Richetelli Jan 2020

Statistical Evaluation Of Randomly Acquired Characteristics On Outsoles With Implications Regarding Chance Co-Occurrence And Spatial Randomness, Nicole Richetelli

Graduate Theses, Dissertations, and Problem Reports

Footwear evidence holds tremendous forensic value, owing to its ability to formulate linkages between victims, suspects and scenes. Naturally, the strength of these linkages is a function of the perceived clarity, quality and rarity of class, subclass and randomly acquired characteristics (RACs), which are the fundamental outsole features used to formulate source associations. In order to reach a conclusion when performing a footwear comparison, forensic examiners must assign value to the observed similarities and differences that exist between questioned crime scene and test impressions. Embedded within this process is an evaluation of the random association between unrelated shoes as a …


Postmortem Interval Estimation Based On Eukaryotic Community Associated With Soil Under Decomposing Porcine Remains, Amanda M. Haase Jan 2020

Postmortem Interval Estimation Based On Eukaryotic Community Associated With Soil Under Decomposing Porcine Remains, Amanda M. Haase

Master of Science in Forensic Science Directed Research Projects

Recent studies have shown that bacteria associated with soils under a carcass change significantly both temporally and spatially. These studies were done in both laboratory and field conditions, but with limited replications. In addition, limited information exists on temporal and spatial changes in eukaryotic community structure associated with soil under decomposing remains. This study was designed to fill in these gaps and expand on previous studies to improve postmortem interval (PMI) estimation techniques as well as to identify cadaver decomposition islands (CDI) based on eukaryotic community structure associated with soil under vertebrate remains. To accomplish this goal, soil samples were …


Development Of A Quantitative Pcr (Qpcr) Based Method For Studying Temporal Dna Degradation In Waterlogged Bone, Isis Thornton Jan 2020

Development Of A Quantitative Pcr (Qpcr) Based Method For Studying Temporal Dna Degradation In Waterlogged Bone, Isis Thornton

Master of Science in Forensic Science Directed Research Projects

Human activities are often centered around the presence of water, thus it is not surprising that there are many water-related human deaths. Accumulated degree days (ADD), and other aquatic variables may affect DNA retrieval from waterlogged bone. Calcium and collagen in bone can inhibit the PCR necessary to produce an STR profile; the current solution is a time-consuming organic extraction. While there are examples of research on DNA degradation in terrestrial bone over time, there has been little work done on submerged bone samples and they are usually limited to case studies. The major aim of this study was to …


Expanded Testing Of An Integrated Qpcr Mixture Screening Assay Using High Resolution Melt Curve Analysis And Support Vector Machine Modeling, Andrea L. Williams Jan 2020

Expanded Testing Of An Integrated Qpcr Mixture Screening Assay Using High Resolution Melt Curve Analysis And Support Vector Machine Modeling, Andrea L. Williams

Master of Science in Forensic Science Directed Research Projects

In the conventional forensic DNA workflow, the number of contributors in a sample is unknown until the final step of STR analysis. We propose a high-resolution melt curve (HRM) mixture screening assay, which uses support vector machine (SVM) modeling of melt morphologies of D5S818 and D18S51 amplicons integrated into a common qPCR-based human DNA quantification kit, to differentiate between single-source samples (and their genotypes) and mixtures at an earlier stage in the DNA workflow (quantification). Previously, using data generated from whole melt curves, 87.5% of single-source samples and 100% of 1:1 mixture samples (2 contributors) classified accurately.

In this study, …