Improved detection of semen by use of direct acid phosphatase testing

Jw, Lewis; Baird, Andrew D.; McAlister, Colin; Siemieniuk, A.; Blackmore, L.; McCabe, Barbara Coyle; O'Rourke, P.; Parekh, Raj B.; Watson, E. M.; Wheelhouse, M.; Wilson, Neil M.

doi:10.1016/j.scijus.2013.04.009

Cited by 36 publications

(13 citation statements)

References 5 publications

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“…The forensic science community has historically relied on the AP reaction as the best indicator for the presence of sperm. Following a literature search, Lewis reported no scientific basis for the two‐minute AP cutoff time, and additionally, both Lewis and Redhead demonstrated that increasing this cutoff time up to 16 min may be required in certain scenarios. Hofft states that the AP test does not provide reliable information as to the presence of seminal fluid and it is very tenuously related to the number of sperm heads.…”

Section: Discussionmentioning

confidence: 99%

The Persistence of Sperm and the Development of Time Since Intercourse (TSI) Guidelines in Sexual Assault Cases at Forensic Science Ireland, Dublin, Ireland

Casey

Domijan

MacNeill

et al. 2016

Journal of Forensic Sciences

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The persistence of sperm using confirmatory microscopic analysis, the persistence of sperm with tails, time since intercourse (TSI) analysis, and results from the acid phosphatase (AP) reaction from approximately 5581 swabs taken from circa 1450 sexual assault cases are presented. The observed proportions of sperm in the vagina and anus declines significantly after 48 h TSI, and sperm on oral swabs were observed up to 15 h TSI. The AP reaction as a predictor of sperm on intimate swabs is questioned. All AP reaction times gave a low true positive rate; 23% of sperm-positive swabs gave a negative AP reaction time. We show the AP reaction is an unsafe and an unreliable predictor of sperm on intimate swabs. We propose that TSI not AP informs precase assessment and the evaluative approach for sexual assault cases. To help inform an evaluative approach, TSI guidelines are presented.

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Section: Discussionmentioning

confidence: 99%

The Persistence of Sperm and the Development of Time Since Intercourse (TSI) Guidelines in Sexual Assault Cases at Forensic Science Ireland, Dublin, Ireland

Casey

Domijan

MacNeill

et al. 2016

Journal of Forensic Sciences

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“…Although the test is simple, cheap, and rapid there can be issues with reproducibility due to temperature variation at the scene, causing changes in evaporation of the sample [22]. The acid phosphatase (AP) test for semen has been in routine use as early as the 1940s [23], but due to its relatively high falsepositive rate [24] it is unable to be used to as a confirmatory test and has recently been sidelined in favour of immunoassay approaches [25]. A considerable advantage of chemical tests is their low pertest cost, but this is often at the expense of specificity and sensitivity.…”

Section: Chemical Testingmentioning

confidence: 99%

Field-based detection of biological samples for forensic analysis: Established techniques, novel tools, and future innovations

Morrison

Watts

Hobbs

et al. 2018

Forensic Science International

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Field based forensic tests commonly provide information on the presence and identity of biological stains and can also support the identification of species. Such information can support downstream processing of forensic samples and generate rapid intelligence. These approaches have traditionally used chemical and immunological techniques to elicit the result but some are known to suffer from a lack of specificity and sensitivity. The last 10 years has seen the development of field-based genetic profiling systems, with specific focus on moving the mainstay of forensic genetic analysis, namely STR profiling, out of the laboratory and into the hands of the non-laboratory user. In doing so it is now possible for enforcement officers to generate a crime scene DNA profile which can then be matched to a reference or database profile. The introduction of these novel genetic platforms also allows for further development of new molecular assays aimed at answering the more traditional questions relating to body fluid identity and species detection. The current drive for field-based molecular tools is in response to the needs of the criminal justice system and enforcement agencies, and promises a step-change in how forensic evidence is processed. However, the adoption of such systems by the law enforcement community does not represent a new strategy in the way forensic science has integrated previous novel approaches. Nor do they automatically represent a threat to the quality control and assurance practices that are central to the field. This review examines the historical need and subsequent research and developmental breakthroughs in field-based forensic analysis over the past two decades with particular focus on genetic methods Emerging technologies from a range of scientific fields that have potential applications in forensic analysis at the crime scene are identified and associated issues that arise from the shift from laboratory into operational field use are discussed.

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“…The presence and concentration of AP in prepubertal girls is unknown. Analytical techniques to quantify AP (e.g., Brentamine Fast Blue reaction) should be regarded as guide and if result is negative, DNA studies (autosomal STRs and Y-STRs) must proceed [ 35 ]. Indeed, the results of the Brentamine colorimetric reaction may be difficult to interpret due to the interference of fabric colors and therefore may lead to false negative results.…”

Section: Biological Evidencementioning

confidence: 99%

Biological Evidence Management for DNA Analysis in Cases of Sexual Assault

Magalhães

Dinis-Oliveira

Silva

et al. 2015

The Scientific World Journal

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Biological evidence with forensic interest may be found in several cases of assault, being particularly relevant if sexually related. Sexual assault cases are characterized by low rates of disclosure, reporting, prosecution, and conviction. Biological evidence is sometimes the only way to prove the occurrence of sexual contact and to identify the perpetrator. The major focus of this review is to propose practical approaches and guidelines to help health, forensic, and law enforcement professionals to deal with biological evidence for DNA analysis. Attention should be devoted to avoiding contamination, degradation, and loss of biological evidence, as well as respecting specific measures to properly handle evidence (i.e., selection, collection, packing, sealing, labeling, storage, preservation, transport, and guarantee of the chain custody). Biological evidence must be carefully managed since the relevance of any finding in Forensic Genetics is determined, in the first instance, by the integrity and quantity of the samples submitted for analysis.

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Improved detection of semen by use of direct acid phosphatase testing

Cited by 36 publications

References 5 publications

The Persistence of Sperm and the Development of Time Since Intercourse (TSI) Guidelines in Sexual Assault Cases at Forensic Science Ireland, Dublin, Ireland

The Persistence of Sperm and the Development of Time Since Intercourse (TSI) Guidelines in Sexual Assault Cases at Forensic Science Ireland, Dublin, Ireland

Field-based detection of biological samples for forensic analysis: Established techniques, novel tools, and future innovations

Biological Evidence Management for DNA Analysis in Cases of Sexual Assault

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