The isolation of spermatozoa from sexual assault swabs using Proteinase K

Chapman, Russell L.; Brown, Nekeidra; Keating, Sheila

doi:10.1016/s0015-7368(89)73249-7

Cited by 12 publications

(4 citation statements)

References 2 publications

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“…In cases of sexual assault, the primary evidentiary material can be detected in intimate swabs, where spermatozoa and vaginal epithelial cells can be mixed. The application of genetic techniques for the personal identification of the perpetrator/s requires the separation of spermatozoa from mixed cell samples (Chapman et al, 2020). Unfortunately, conventional methods may offer no assurance of effective cell separation (Hutchinson et al, 2019;Puri et al, 2019), so immunomagnetic bead separation techniques can be tested, based on the binding of an antibody, Hyaluronidase PH-20 (SPAM1), which targets the spermatozoa head.…”

Section: Cytologymentioning

confidence: 99%

The Role of Histology in Forensic Investigations

Guareschi,

Kelleher,

Magni

2024

Preprint

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histology, the processing and staining of cells, tissues and organs to highlight contrast, visualize and analyze their microstructure under microscopy, encompasses a vast array of techniques used to confirm, refine, or refute the macroscopic findings in forensic investigations, for example in the case of autopsies. This review presents several applications of histological protocols, staining methods and techniques to case studies, with the aim of illustrating the established, current and potential applications of histological investigations to forensic sciences. The list of disciplines include anthropology, cytology, dendrochronology, diatomology, entomology, fiber analysis, palynology,human and veterinary pathology, taphonomy and thanatology.

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Section: Cytologymentioning

confidence: 99%

The Role of Histology in Forensic Investigations

Guareschi,

Kelleher,

Magni

2024

Preprint

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“…Frequently, mixed stains in sexual assault cases contain sperm cells, which are typically separated from nonsperm cells using differential lysis procedures (a two-step method) because sperm nuclei are ramified with crosslinked thiol-rich proteins and can be separated from the female component by centrifugation. Differential extraction is the primary method in forensic DNA laboratories for the isolation and lysis of spermatozoa [2][3][4][5][6]. Ideally, DNA isolated through differential extraction generates two single-source autosomal DNA profiles [5,6] for STR (short tandem repeats) analysis.…”

Section: Introductionmentioning

confidence: 99%

“…Differential extraction is the primary method in forensic DNA laboratories for the isolation and lysis of spermatozoa [2][3][4][5][6]. Ideally, DNA isolated through differential extraction generates two single-source autosomal DNA profiles [5,6] for STR (short tandem repeats) analysis.…”

Section: Introductionmentioning

confidence: 99%

A novel three‐step DNA extraction method for mixed bloodstains

Huang,

Huang

2023

Electrophoresis

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Mixed DNA samples from at least two contributors can be present at a crime scene, which could be the most crucial piece of genetic evidence. The mixed stains in sexual assault cases are typically separated using differential lysis procedures (a two‐step method). Blood mixed stains, however, are usually difficult to separate. In this work, we propose that a mixed stain comprises three layers, that is, (1) the upper layer which is primarily made up of cells from one contributor; (2) the middle layer which is a similar mixture from two contributors; and (3) the lower layer which primarily comprises cells from the other contributor. Based on this concept, a novel three‐step DNA extraction method was proposed to solve the challenge involving bloodstains from two contributors. In the experiment, we extracted three layers DNA from mixed bloodstains using three steps. As a result, single‐source DNA and approximate single‐source DNA were detected from steps 1 and 3, respectively. This study demonstrates that the DNA from some mixed blood stains could be effectively separated following an appropriate extraction strategy, providing valuable insights, and serving as a reference for future examination of blood mixtures.

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“…This method combines sodium dodecyl sulfate (SDS) and Pro K, which selectively lyse epithelial cells, while the spermatozoa heads remain intact. Forty‐two samples were identified as positive for the presence of spermatozoa prior to treatment with SDS and Pro K. Following SDS/Pro K treatment of the remaining sample extract, spermatozoa were detected in the original 42 samples and in nine additional samples .…”

mentioning

confidence: 99%

A Comparison of the Effectiveness of Swabbing and Flossing as a Means of Recovering Spermatozoa from the Oral Cavity

Roberts

Johnson

Cruz

et al. 2014

Journal of Forensic Sciences

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This study examined whether flossing the teeth is a more effective collection method in recovering spermatozoa than conventional swabbing techniques. It was hypothesized that inclusion of flossing as a collection method would extend the recovery of spermatozoa to longer postcoital intervals (PCIs). Eighteen individuals provided 174 oral cavity samples. Successful recovery of spermatozoa was assessed with respect to the collection method and reported activity in the oral cavity during the PCI. Samples were subjected to a differential extraction procedure prior to microscopic evaluation of the extracted pellet. The results indicate that swabbing is more effective than flossing when the PCI falls within 1.5-12 h. However, spermatozoa were recovered from seven floss samples where the corresponding swabs gave negative results. When combining the results from the two collection methods, the percentage of subjects from whom spermatozoa are recovered increases for each PCI beyond the 0-h interval.

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The isolation of spermatozoa from sexual assault swabs using Proteinase K

Cited by 12 publications

References 2 publications

The Role of Histology in Forensic Investigations

The Role of Histology in Forensic Investigations

A novel three‐step DNA extraction method for mixed bloodstains

A Comparison of the Effectiveness of Swabbing and Flossing as a Means of Recovering Spermatozoa from the Oral Cavity

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