Home
Resource
Stabilizing information content in DNA evidence to improve lab-to-lab inference
PDF
PDF format is widely accepted and good for printing.
Plug-in required
PDF-1(20.07 MB)
Citation & Export
View Usage Statistics
Staff View

Citation & Export
Hide

Simple citation

Malek, Laura. Stabilizing information content in DNA evidence to improve lab-to-lab inference. Retrieved from https://doi.org/doi:10.7282/t3-2eh1-rh05

Export

Click here for information about Citation Management Tools at Rutgers.

Statistics
Hide

Description

TitleStabilizing information content in DNA evidence to improve lab-to-lab inference
NameMalek, Laura (author); Shain, Daniel (chair); Grgicak, Catherine (internal member); Butler, Monroe (outside member); Hutley, Ja'Neisha (outside member); Rutgers University; Camden Graduate School
Date Created2019
Other Date2019-05 (degree)
SubjectBiology, DNA, DNA fingerprinting, Forensic genetics
Extent1 online resource (xii, 62 pages) : illustrations
DescriptionBiological evidence acquired from crime scenes often contains mixtures of partial genomes from an unknown number of cells from any number of unknown contributors. Therefore, assessing the probability that a person contributed to an evidentiary item becomes a complicated combinatorial challenge, which is made more difficult in the presence of extraneous signal originating from random allele drop-in events or stutter artifacts. Not only does forensic DNA signal consist of extraneous signal, but it may exhibit significant levels of allele non-detection, often referred to as allele drop-out. Given these two sources of drop-out and the desire to stabilize inference results between laboratories, it is of interest to develop laboratory protocols aimed at reducing 1) drop-out due to sampling effects; and 2) drop-out due to detection effects.
In Phase I of the project we determined, through a DNA simulator named ValiDNA, that the optimal analytical conditions consisted of 29 PCR cycles and a 25 second injection. Once optimal analytical conditions were determined, a variety of collection/extraction pipelines were evaluated. In particular, cutting versus swabbing techniques were tested, as were silica and direct-to-PCR extraction methods. Notably, coupling a cotton swab collection with a silica-based extraction forces DNA volume partitions be processed through to PCR, while the FLOQSwab® and PicoPure® method is a ‘direct-to-PCR’ method that does not fractionate the extract. Experimentation demonstrated that there was not a significant difference between the four pre-PCR processes tested.
In conclusion, this work demonstrates that stabilizing the DNA signal acquired through PCR-based techniques is possible through the implementation of a simulation-based approach, using the laboratories’ own data to parameterize an in-silico DNA laboratory. Notably, if all laboratories choose parameters that render consistent detection of a single-copy of DNA, the evidentiary signal between laboratories will contain the same information contents, substantially improving evidential inference at a national scale. Additionally, using optimal analytical pipelines clearly demonstrates that direct PCR methods are not necessarily beneficial when attempting low-copy number interpretation; rather, multiple replicate amplifications of DNA rendered from a swab-silica pre-PCR pipeline is preferred.
NoteM.S.
NoteIncludes bibliographical references
Genretheses, ETD graduate
Persistent URLhttps://doi.org/doi:10.7282/t3-2eh1-rh05
LanguageEnglish
CollectionCamden Graduate School Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.
Version 8.5.5
Rutgers University Libraries - Copyright ©2024