| الوصف: |
DNA has long been the “gold-standard” for the identification of organisms. It plays a central role in revealing the past by answering the questions who, what, where and when. A priori knowledge of the source of the DNA from a specimen can yield answers that relate to evolution, migration, the spread of disease, familial relationships and criminal activity. A significant challenge across the biological sciences is the interpretation of DNA profiles generated from non-pristine or complex samples, namely when samples are of low quality, low copy number, or contain multiple contributors. This is of particular concern in subfields focusing on ancient DNA, forensic DNA and processed food DNA, where non-pristine DNA samples are commonplace. Many times, the interpretational complexity of these sample types preclude the ability to generate high confidence conclusions. However, it is possible to decrease interpretational difficulty through: (1) wet-bench procedures that maximize yield and enrich for the DNA targets of interest and (2) implementation of computationally advanced software solutions that intelligently reduce complexity and increase the efficiency of analyses. The work presented herein represents a multifaceted approach to the analysis of complex DNA samples through four distinct yet contextually related projects: (1) Improvements in DNA isolation methods can significantly decrease the complexity of downstream analyses. The first section describes a method to isolate opium poppy (Papaver somniferum L.) DNA from heroin. The method uses a combination of commercial DNA extraction methods, post-extraction purification and a dual stage, dual polymerase PCR amplification. DNA was successfully isolated from raw and cooked opium and black tar, white and brown powder heroin. (2) The second section describes a pre-extraction cell targeting and collection method for sexual assault samples using the DEPArray™ instrument. We demonstrate that DEPArray™ mediated cell targeting leads to single source male profiles in 96.2% of ... |
