General Crime Scene Procedure
Paul T. Jayaprakash in Crime Scene Investigation and Reconstruction, 2023
Disturbances leading to physical evidence contamination: Contamination is the process of transfer of extraneous matter between the collector and the evidence or multiple pieces of evidence, producing tainted evidence that cannot be used in the subsequent investigation (Saferstein, 2019). As the definition implies, contamination pertains to collectable evidence, and SOCOs are required to follow the standard protocols to ensure that the evidence collected can be considered as ‘not contaminated’ and as qualified for analysis and interpretation. While the SOCOs must strive to follow the standard operating procedures for contamination prevention which have been reiterated time and again (Houck et al., 2012; Fisher and Fisher, 2012; Suboch, 2016; Saferstein, 2019), they must routinely adhere to the following essential precautionary measures which should also be noted in their report. Always use latex gloves and/or disposable forceps when touching evidence, especially those requiring DNA analysis, and make sure to change the gloves for each evidence when they are in multiples. Remember that DNA profiling requires absolutely uncontaminated samples.Clean and sanitize all equipment that are not disposable before and after visiting a crime scene and between collecting each piece of evidence.
An Introduction to Statistics and Proposition Setting
Jo-Anne Bright, Michael D. Coble in Forensic DNA Profiling, 2019
The first statement can be rewritten in symbols as Pr(4 legs | cow) = 1 and the second statement is Pr(cow | 4 legs) = 1. These are obviously not the same. The second statement is clearly false,* there are many other four-legged animals. It is much harder detecting a transposed conditional in terms of DNA profiling evidence. Consider the following reports from the New Zealand press: ESR scientists say the DNA found on and inside the gloves is 800 billion times more likely to come from Mitchell than anyone else.†Nearly two hours into the interview, Pascoe reveals that DNA discovered on a retraction letter sent to police was 260 times more likely to belong to Kerr or a male relative of his than any other male.‡Institute for Environment(al) and Scientific Research (ESR) scientist Stephanie Opperman stated that blood found in Merritt's bathroom was one trillion times more likely to have come from Ms. Ross than a random member of the public. Fellow forensic scientist Timothy Power said the YSTR DNA found under Ms. Ross’ right hand fingernails was 430 times more likely to have come from Merritt than a random member of the public.*Some of the retested samples contained DNA which was “one billion billion” times more likely to have come from Christine Lundy than anyone else, Vintiner said.†
Principles of forensic science and crime scene investigation
Jason Payne-James, Richard Jones in Simpson's Forensic Medicine, 2019
DNA profiling is often used to identify potential individuals who have handled an item, depositing skin cells or cell-free DNA (cfDNA), such as on a door handle, for example. It can also be used to assist in the identification of wearers of garments such as gloves or hats and shoes. In some instances, skin cells may be visible microscopically, and sampling appropriately directed. In other instances, a whole area may need to be speculatively swabbed.
The molecular basis of platelet biogenesis, activation, aggregation and implications in neurological disorders
Published in International Journal of Neuroscience, 2020
Abhilash Ludhiadch, Abhishek Muralidharan, Renuka Balyan, Anjana Munshi
Various studies carried out in vascular disorders involving platelets did not find a significant biomarker. More than one impaired factors have surfed and therefore, it would be appropriate to combine all these and generate a comprehensive profile. Another approach to overcome heterogeneity would be sub categorization of the complex diseases based on their genetic architecture as well as the response to treatment. No doubt further studies as warranted to identify novel markers not known currently. The current diagnostic approaches are getting evolved based on the DNA profiling heading towards the personalized medicine. Since the platelets are easily obtained from the patients they are useful in carrying out expression studies in platelets both at transcriptomic and proteomic level. This has the potential of deciphering the signaling pathways as well as pathophysiological mechanisms. In addition it also quite easy to isolate the platelets in non-active states and also activating them under laboratory conditions using different agonists. This approach has helped to understand the specific disease mechanisms in patients affected with cardiovascular, neurovascular or other complex diseases based on the knowledge significant to megakaryocytes and biology of the platelets.
Genetic admixture history and forensic characteristics of Turkic-speaking Kyrgyz population via 23 autosomal STRs
Published in Annals of Human Biology, 2019
Pengyu Chen, Xing Zou, Biao Wang, Mengge Wang, Guanglin He
Short Tandem Repeats (STRs), a kind of DNA sequence containing a variable number of tandemly repeated short sequence motifs (2 ∼ 6 bp) and widely distributed in the human genome, are amenable to analysis by both capillary electrophoresis (CE)-based and massively parallel sequencing (MPS)-based genotyping technologies (Kayser and de Knijff 2011). Autosomal STRs (A-STRs) have become the gold standard in paternity testing and individual identification (He, Wang, Liu, et al. 2018). DNA profiling with sets of highly polymorphic STR loci to identify perpetrators, disaster victims and family members has proven to be very successful for nearly 30 years (Hagelberg et al. 1991; Kayser and de Knijff 2011). However, the genetic polymorphisms and forensic efficiency of forensically used A-STRs in the Turkic-speaking Kyrgyz residing in the Kizilsu Kyrgyz Autonomous Prefecture, as well as the genetic homogeneity and heterogeneity between the Kyrgyz group and reference populations, remain unclear.
Genetic analysis of primary renal cell carcinoma to determine treatment approaches
Published in Expert Review of Precision Medicine and Drug Development, 2021
Viktoria Stühler, Steffen Rausch, Arnulf Stenzl, Jens Bedke
Subsequent biomarker analyses from pre-treatment tissue of patients enrolled on CheckMate 214 (NCT02231749) were presented at ASCO congress 2020. Just under half the tissue samples from each treatment arm underwent DNA profiling by whole-exome sequencing (262 for ipilimumab plus nivolumab, 219 for sunitinib), and approximately 100 samples in each arm were profiled by RNA sequencing. For RNA analysis, previously derived RNA expression signatures associated with angiogenesis or immune infiltration from IMMotion150 and JAVELIN Renal 101 were applied. Although sunitinib treated tumors with a high IMmotion150 angiogenesis score showed a higher overall response rate (ORR) and better PFS (HR 0.6, p = 0.02), this did not extend to OS benefit. A lower angiogenesis gene-signature score was associated with higher ORR in patients treated with ipilimumab plus nivolumab, and no association was observed between survival and immune-related gene expression signatures. Immune-related gene expression signatures previously derived from patients with mRCC treated in IMmotion 150 or JAVELIN Renal 101 did not predict PFS or OS with ipilimumab plus nivolumab. Gene enrichment analysis of Hallmark gene sets (MSigDB) was used to identify key biological processes represented by genes differentially expressed in patients with PFS of more or less than 18 months treated with ipilimumab plus nivolumab. Here, a higher expression of Hallmark inflammatory response and Hallmark epithelial-mesenchymal transition gene sets was associated with prolonged PFS with ipilimumab plus nivolumab [25].
Related Knowledge Centers
- DNA
- Forensic DNA Analysis
- Microsatellite
- Minisatellite
- Variable Number Tandem Repeat
- Blood
- Saliva
- DNA Paternity Testing
- Twin
- Locus