Advantage of ForensiX Swabs in Retrieving and Preserving Biological Fluids

Mawlood, Shakhawan K.; Alrowaithi, Majid; Watson, Nigel

doi:10.1111/1556-4029.12704

Cited by 11 publications

(17 citation statements)

References 9 publications

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“…Biological samples were collected after ethical approved: a consent form was discussed and signed by the volunteers. Blood swabs were taken using ForensiX tubes by the investigator, its advantages detailed in our previous study [20]. To decrease the biological parameter diversity, only females were recruited (80 volunteers), their ethnic background (Kurdish) and age range (18-91 years) as phenotype information were recorded independently.…”

Section: Methodsmentioning

confidence: 99%

The EpiTect Methyl qPCR Assay as novel age estimation method in forensic biology

Mawlood

Dennany

Watson

et al. 2016

Forensic Science International

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Human aging is associated with epigenetic modification of the genome. DNA methylation at cytosines appears currently as the best characterised modification that occurs during the mammalian lifetime. Such methylation changes at regulatory region can provide insights to track contributor age for criminal investigation. The EpiTect Methyl II PCR system (QIAGEN) was used to compare methylation levels of CpG islands in the promoter regions of a number of age related genes, of which four successfully showed changes across the lifespan (NPTX2, KCNQ1DN, GRIA2 and TRIM58). This technique is based on the detection of remaining input genome after digestion with a methylation-sensitive restriction enzyme. This study examined DNA specimens from 80 female subjects of various ages (18-91 years) obtained from blood, using primers designed to flank the studied gene loci. The data obtained from DNA methylation quantification showed successful discrimination among volunteered ages. Overall, the difference between predicted and real age was about 11 years and absolute mean differences (AMD) was only 7.2 years error. We suggest the EpiTect system can be used as fast and simple innovative tool in future forensic age estimation.

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Section: Methodsmentioning

confidence: 99%

The EpiTect Methyl qPCR Assay as novel age estimation method in forensic biology

Mawlood

Dennany

Watson

et al. 2016

Forensic Science International

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“…Following operational procedures in place within the partner institutions, samples are routinely stored at room temperature (RT) before being analyzed. Although RT storage is convenient since it does not require cooling devices, studies have shown that DNA damage may already occur a few hours after collection when swabs are stored wet [18][19][20]. This could be problematic since swabs can be stored weeks or months within police forces and/or the DNA laboratory before being processed.…”

Section: Second Part: Dna Preservationmentioning

confidence: 99%

Touch DNA collection – Performance of four different swabs

Comte

Baechler

Gervaix

et al. 2019

Forensic Science International: Genetics

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A collaborative study conducted by three police forensic units, a DNA laboratory, and a forensic academic institute was undertaken in order to compare the performance of four different swabs in controlled and quasioperational conditions. For this purpose, a reference swab (Prionics cardboard evidence collection kit) currently used within the police forensic units and 3 challenger swabs (COPAN 4N6FLOQSwabs™ (Genetics variety), Puritan FAB-MINI-AP and Sarstedt Forensic Swab) were used for collecting DNA traces from previously used items (referred as "touch DNA" in this article) including on 60 collars, 60 screwdrivers and 60 steering wheels obtained from volunteers. For each comparison, the surface considered was divided into two equal components; one was sampled with the reference swab and the other with one of the three challenger swabs. This lead to a total of 360 samples. Conclusions were consistent within the four operational partners. From a practical point of view, the COPAN 4N6FLOQSwabs™ (Genetics variety) was judged the most convenient to use. Furthermore, it allowed the recovery of significantly more DNA from collars (0.65 vs 0.13 ng/μL) and steering wheels (2.82 vs 1.77 ng/μL), and a similar amount of DNA from screwdrivers (0.032 vs 0.026 ng/μL) compared with the Prionics reference swab. The two other challenger swabs provided results that were not significantly different from the reference swab, except for the Puritan swab, whose performance was significantly lower for steering wheels (0.37 vs 0.58 ng/μL). As part of a conservation study, 50 μL of a blood dilution (1/4 with PBS) was deposited on a total of 105 COPAN (Genetics and Crime Scene varieties), Prionics and Sarstedt swabs. They were stored within a cupboard at room temperature. The integrity of the recovered DNA was evaluated with NGM SElect™ DNA profiles after different time-spans ranging from 1 day to 12 months by comparing the height difference of the peaks occurring at the shortest and longest loci, respectively. DNA seemed to remain stable, except when using the COPAN 4N6FLOQSwabs™ treated with an antimicrobial agent (Crime scene variety), which resulted in significant DNA degradation. Following these tests, the COPAN 4N6FLOQSwabs™ (Genetics variety), a model with a desiccant, was selected for further testing in fully operational conditions.

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“…For forensic (human biological) applications cotton , foam , nylon flocked , polyester , and rayon (viscose) swabs have been tested with epithelial , saliva and vaginal samples and have been expressed in terms of the number of alleles present in the DNA‐profile (), the DNA quantity/yield (ng), the concentration (ng/μL) or percentage . The various swabs have been ranked by Verdon et al according to their combined collection and extraction efficiency.…”

mentioning

confidence: 99%

“…The various swabs have been ranked by Verdon et al according to their combined collection and extraction efficiency. Typical extraction volumes for forensic applications have been in the order of microliters . Only a few experiments have been performed to determine the extraction efficiency, whereas a swab may have high collection properties, but bad performance upon release of the sample .…”

mentioning

confidence: 99%

“…Typical extraction volumes for forensic applications have been in the order of microliters . Only a few experiments have been performed to determine the extraction efficiency, whereas a swab may have high collection properties, but bad performance upon release of the sample . Although the absorption capacity can have a substantial influence on the DNA extraction and recovery efficiency of a swab , none of the reported investigations has taken this parameter into account for various types of swabs.…”

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The Extraction and Recovery Efficiency of Pure DNA for Different Types of Swabs

Bruijns

Tiggelaar

Gardeniers

2018

Journal of Forensic Sciences

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The extraction and recovery efficiency of swabs used to collect evidence at crime scenes is relatively low (typically <50%) for bacterial spores and body fluids. Cell-free deoxyribonucleic acid (DNA) is an interesting alternative compared to whole cells as a source for forensic analysis, but extraction and recovery from swabs has not been tested before using pure DNA. In this study cotton, foam, nylon flocked, polyester and rayon swabs are investigated in order to collect pure DNA isolated from saliva samples. The morphology and absorption capacity of swabs is studied. Extraction and recovery efficiencies are determined and compared to the maximum theoretical efficiency. The results indicate that a substantial part of DNA is not extracted from the swab and some types of swab seem to bind effectively with DNA. The efficiency of the different types of swab never exceeds 50%. The nylon flocked 4N6FLOQSwab used for buccal sampling performs the best.

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Advantage of ForensiX Swabs in Retrieving and Preserving Biological Fluids

Cited by 11 publications

References 9 publications

The EpiTect Methyl qPCR Assay as novel age estimation method in forensic biology

The EpiTect Methyl qPCR Assay as novel age estimation method in forensic biology

Touch DNA collection – Performance of four different swabs

The Extraction and Recovery Efficiency of Pure DNA for Different Types of Swabs

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