Direct PCR Improves the Recovery of DNA from Various Substrates

Templeton, Jennifer E.L.; Taylor, Duncan; Handt, Oliva; Skuza, Pawel

doi:10.1111/1556-4029.12843

Cited by 49 publications

(24 citation statements)

References 25 publications

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“…These data suggest that exhibits suspected to contain limited DNA, such as those touched for a short period of time, can be processed by direct PCR with either the GlobalFiler® or Identifiler® Plus STR kits and achieve significantly greater success rates than if the sample underwent extraction prior to amplification. While these data are supported by previous studies [6,7,14], our additional data supports the use of Identifiler® Plus for the amplification of touch DNA.…”

Section: Direct Pcr Vs Extractionsupporting

confidence: 89%

“…There is a growing interest in the use of direct PCR to maximise the amount of DNA profile information obtained from forensic evidence, particularly from trace or touch DNA samples. Since its first application in forensic science in 2010 [1], direct PCR has been applied to single hairs [2], nails [3], fibres [4], bullet cartridges [5], different surface types [6,7], and more recently fingermarks [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…The first use of direct PCR employed SGM Plus® [1] with further studies using NGM SElect™ [2,4,8]. As the commercially available kits have increased the number of loci available to amplify, so has the ability of the buffers used to overcome inhibitors [7] as well as the activity of the enzyme. GlobalFiler® is one of the latest commercial STR kits launched by Thermo Fisher Scientific and amplifies 24 loci, comprising 21 autosomal STRs, 1 Y-STRs and 1 Indel.…”

Section: Introductionmentioning

confidence: 99%

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DNA profiles generated from a range of touched sample types

Martin

Blackie

Taylor

et al. 2018

Forensic Science International: Genetics

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Direct PCR from touch DNA has a range of potential applications in the field of forensic investigation for exhibit examination that, under standard extraction methods, rarely produce informative DNA profiles. Previous studies from 'touch DNA' have focussed on fingermarks created under laboratory conditions. Here we report on successful STR DNA profiling from a range of touched items. Direct PCR, with no increase in cycle number, was performed after eight different sample types, typical of those submitted for forensic investigation, were handled by volunteers for a maximum of 15 s to deposit trace amounts of their DNA. Amplifications were performed using either GlobalFiler or Identifiler Plus following manufacturer's instructions. These two kits were chosen deliberately as many laboratories worldwide have adopted and validated them in their workflow, thus allowing for direct PCR to be incorporated within their practises easily. It was found that informative STR profiles were obtained from all eight substrates using both STR kits. Identifiler Plus out-performed GlobalFiler in terms of the percentage of alleles amplified using the direct PCR approach. Both generated informative profiles from all items and all individuals, at different rates, with Identifiler Plus being informative in a larger percentage of samples. GlobalFiler produced profiles with an average of 60% ± 24% (36 ± 15 alleles) alleles present while Identifiler Plus produced profiles with an average of 96% ± 4% (31 ± 1 alleles) alleles present. A comparison was made between the direct PCR approach and subjecting touched samples to a standard DNA extraction process, both using Identifiler. An average of 4% of profiles were informative for samples that underwent extraction with 100% being informative from the same subset of samples amplified by direct PCR. Our findings further demonstrate the success of direct PCR to enhance the STR DNA profiles from touch DNA. Further, Identifiler Plus was found to generate informative profiles more often than GlobalFiler. Direct PCR is fast, simple, and non-destructive of evidence with the ability to generate informative genetic data where standard methods are likely to fail.

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Section: Direct Pcr Vs Extractionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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DNA profiles generated from a range of touched sample types

Martin

Blackie

Taylor

et al. 2018

Forensic Science International: Genetics

Self Cite

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“…Loss of DNA during the extraction process is unavoidable. The loss can be caused by transfer steps, incomplete cell lysis [28], incomplete cell elution [29], or other reasons mentioned in [30]. For one-tube extraction methods like Chelex [31], there is no loss of DNA due to transfer steps.…”

Section: Resultsmentioning

confidence: 99%

Characterization of degradation and heterozygote balance by simulation of the forensic DNA analysis process

2016

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Simulation experiments were used to show the impact of varying extraction efficiency, aliquot proportion, and PCR efficiency on the heterozygote balance of a range of diploid and haploid cells. Reducing either parameters introduces variance. It is well-known that the variance in heterozygote balance increases as the amount of DNA is reduced. Surprisingly the distribution is in fact diamond shaped — the variance start to decrease at very low amounts of DNA. Simulations suggest that pristine diluted DNA is an acceptable approximation in validations to infer heterozygote balance. However, the difference in distribution of the variance between diploid and haploid cell types may, under some circumstances, need to be considered in statistical models. Finally, we exemplify how simulations can be used to predict the outcome of PCR for degraded samples. Visualizing the predicted DNA profile as an electropherogram can help to identify the best approach for sample processing.Electronic supplementary materialThe online version of this article (doi:10.1007/s00414-016-1453-x) contains supplementary material, which is available to authorized users.

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“…Alternatively, swabs or other materials can be used to remove touch DNA from a substrate and then the swab head can be introduced directly into the PCR reaction. The successful use of direct amplification for touch DNA recovery has been widely reported from a range of sample types [7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Touch DNA on objects can be analysed at low cost using simplified direct amplification methods

Gammon

Murray-Jones

Shenton

et al. 2019

Preprint

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Previous studies reported in the literature demonstrate that a range of sampling vehicles can be used effectively for forensic analysis of human DNA in direct amplification reactions. In this study we compared Copan microFLOQ ® swabs with a range of alternative sampling vehicles, using touch DNA samples donated by 15 different volunteers. MicroFLOQ swabs performed well, as did 3 mm diameter discs punched from analytical filter paper. The 3 mm discs could be used in a 5 µl PCR volume, increasing sensitivity, and reducing costs when compared with other methods that require a larger PCR volume. Other inert sampling vehicles, such as interdental toothbrushes and toothpicks also gave good results in direct amplification. The study found a large variation in results between the 15 touch DNA donors, demonstrating the importance of validating touch DNA recovery techniques with a large pool of donors.touch DNA | direct amplification | forensic DNA analysis | trace evidence

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Direct PCR Improves the Recovery of DNA from Various Substrates

Cited by 49 publications

References 25 publications

DNA profiles generated from a range of touched sample types

DNA profiles generated from a range of touched sample types

Characterization of degradation and heterozygote balance by simulation of the forensic DNA analysis process

Touch DNA on objects can be analysed at low cost using simplified direct amplification methods

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