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Blackmore L, Hadley Cabral de Almada C, Poulsen F, Prasad E, Kotzander J, Paton K, Hitchcock C, Nadort A. Evaluation of the microbial wet-vacuum system (M-Vac®) for DNA sampling from rough, porous substrates, and its compatibility with fully automated platforms. Forensic Sci Int 2024; 361:112079. [PMID: 38850613 DOI: 10.1016/j.forsciint.2024.112079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/10/2024]
Abstract
DNA retrieval methods traditionally used during forensic evidence recovery including swabbing and tape lifting, can have limited effectiveness when used on porous, rough substrates such as bricks and carpet. This is possibly due to the DNA material being dispersed and unreachable for surface sampling techniques. In this evaluation we investigated the effectiveness of the Microbial Wet-Vacuum System (M-Vac®; M-Vac® Systems, Inc., Sandy, UT), as it has been reported to retrieve greater amounts of DNA material from challenging exhibits. A four-stage evaluation was conducted, starting with seeding carpet and brick substrates with a known donor's saliva in two dilutions and comparing the DNA recovery of tape lifting, swabbing, and the M-Vac®. A victim struggle scenario on carpet was then mimicked to compare trace DNA recovery by each method. Two mock scenarios were also conducted; a shirt was submerged in a creek bed for a period of five days to sample for the wearer's DNA, and a car boot was sampled to assess the possibility of recovering a victim's DNA amongst background DNA from the usual car occupants. Finally, the compatibility of the M-Vac® sampling process was optimised for the fully automated DNA lysis and extraction platforms used in the NSW (Australia) jurisdiction by comparing filter subsampling methods. The results from the study were mixed. For bricks, none of the collection methods were effective in retrieving DNA. On carpet, the M-Vac® retrieved the greatest quantities of DNA from the saliva-seeded samples, however, tape lifts outperformed all methods for 'touch' DNA recovery. The M-Vac® retrieved the greatest amount of DNA from the t-shirt recovered from a creek bed as it was able to retrieve the embedded DNA. The final mock case car boot scenario resulted in greater victim DNA recovery from tape lifts, with the M-Vac® more likely to recover mixtures too weak and/or complex to be interpreted. Finally, operational considerations regarding the compatibility of the M-Vac® system with fully automated DNA lysis and extraction are discussed. Considering the substantial time and cost to deploy the M-Vac®, it is recommended to be utilised in casework only after swabbing and tape lifting methods have failed to yield sufficient DNA material, where the substrate properties would likely benefit from the M-Vac's® niche capabilities for retrieving embedded DNA, and low levels of background DNA may be anticipated.
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Affiliation(s)
- Laura Blackmore
- NSW Police Force, Forensic Evidence & Technical Services Command, Australia; Centre for Forensic Science, University of Technology Sydney, Australia
| | | | - Felicity Poulsen
- NSW Health Pathology, Forensic & Analytical Science Service, Forensic Biology/DNA Unit, PO Box 162, Lidcombe, NSW 1825, Australia
| | - Elisha Prasad
- NSW Police Force, Forensic Evidence & Technical Services Command, Australia
| | - Jessica Kotzander
- NSW Police Force, Forensic Evidence & Technical Services Command, Australia
| | - Kelly Paton
- NSW Police Force, Forensic Evidence & Technical Services Command, Australia
| | - Catherine Hitchcock
- NSW Health Pathology, Forensic & Analytical Science Service, Forensic Biology/DNA Unit, PO Box 162, Lidcombe, NSW 1825, Australia
| | - Annemarie Nadort
- NSW Police Force, Forensic Evidence & Technical Services Command, Australia.
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Grosjean F, Favre M, Castella V. Comparison between MACSprep™ forensic sperm microbead kit and Erase Sperm Isolation kit for the enrichment of sperm fractions recovered from sexual assault samples. Int J Legal Med 2023; 137:267-278. [PMID: 35773355 PMCID: PMC9816209 DOI: 10.1007/s00414-022-02861-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/21/2022] [Indexed: 01/11/2023]
Abstract
Sexual assault samples often contain mixtures of cells coming from at least two donors. Ideally, one would need to separate the cells into two cellular fractions: one consisting of the alleged aggressor's spermatozoa (the sperm fraction) and the other containing the victim's epithelial cells (the non-sperm fraction). This separation increases the probability of obtaining the alleged offender's autosomal DNA profile. However, spermatozoa are often collected along with an excess of biological material originating from the victim, and with unfavorable male:female biological material ratios, the absence of separation could result in the PCR amplification of the victim's DNA profile only. Several approaches are available to enrich/purify the spermatozoa present on sexual assault samples. In this paper, we compare a new method, the MACSprep™ Forensic Sperm MicroBead Kit (MACSprep, based on microbeads conjugated with antibodies bound to spermatozoa and their retention within a magnetic column) with the Erase Sperm Isolation Kit (Erase, a standard differential lysis separation procedure combined with a specific removal of free DNA) routinely used in our lab. The performance of both kits was tested using sets of vaginal and buccal swabs loaded with different dilutions of sperm, or azoospermic semen, representing a total of 120 independent samples. For the samples containing undiluted sperm, an average recovery of 58% was observed for the MACSprep's sperm fractions and 43% for Erase's. Significantly better recovery of azoospermic semen was observed in MACSprep's non-sperm fractions (~ 85%) compared to Erase (~ 28%). Erase performed significantly better than MACSprep in terms of recovery for diluted sperm samples (1:10 to 1:800 sperm dilutions) in the presence of vaginal cells, while the purities of the achieved sperm fractions were in favor of MACSprep for the highest sperm dilutions tested. Similar trends were observed with buccal swabs loaded with 1:200 sperm dilutions. Increased sperm dilutions on vaginal swabs resulted in higher variability in the male material recovered, whatever the separation method used. Both methods were easy to perform and resulted in male DNA extracts ready to use in less than 2 h. Both kits showed their specificities in terms of recovery efficiency and purity of the sperm fractions. Ideally, additional experiments should be performed in different laboratories, using workflow and chemistries different than ours, to better define the peculiarities observed with MACSprep for high dilutions. Improving the recovery of MACSprep for diluted samples, in addition to its better purity observed in the experiments performed, could make it a method of choice for laboratory workflow, despite MACSprep's current price per sample being about twice the price of Erase's.
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Affiliation(s)
- Frederic Grosjean
- grid.411686.c0000 0004 0511 8059Forensic Genetics Unit, University Center of Legal Medicine, Lausanne – Geneva, Lausanne University Hospital and University of Lausanne, Chemin de la Vulliette 4, 1000 Lausanne 25, Switzerland
| | - Marylou Favre
- grid.411686.c0000 0004 0511 8059Forensic Genetics Unit, University Center of Legal Medicine, Lausanne – Geneva, Lausanne University Hospital and University of Lausanne, Chemin de la Vulliette 4, 1000 Lausanne 25, Switzerland
| | - Vincent Castella
- grid.411686.c0000 0004 0511 8059Forensic Genetics Unit, University Center of Legal Medicine, Lausanne – Geneva, Lausanne University Hospital and University of Lausanne, Chemin de la Vulliette 4, 1000 Lausanne 25, Switzerland
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Nakagawa T, Doi M, Nishi K, Sugahara T. Advantages of filtration method for sperm-DNA genotyping in sexual assault cases. Leg Med (Tokyo) 2022; 54:101988. [PMID: 34915337 DOI: 10.1016/j.legalmed.2021.101988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 10/20/2021] [Accepted: 10/26/2021] [Indexed: 01/12/2023]
Abstract
Differential extraction (DE) is a conventional method to isolate sperms from forensic semen samples (e.g. vaginal swab containing semen) for sperm-DNA genotyping. Subsequent to selective digestion of somatic cells in a mixture sample, sperms are collected and purified as a pellet by repetitive centrifugation based on the specific gravity of sperm heads. However, the centrifugation operation requires a technical proficiency and an extensive time to prevent a loss of sperms from the pellet as much as possible. Therefore, we devised a "filtration method (FM)", in which a vacuum filtration operation based on the size of sperm heads is adapted, instead of DE, for isolation of sperms without any loss in principle. Sperms are collected and purified on a polycarbonate membrane filter. In this study, we have compared results of forensic assays by DE and FM for sperm-DNA genotyping from forensic semen samples. Consequently, FM had advantages of easy operation, timesaving, and high yield of sperms from semen samples compared with DE, although FM had a comparable ability to DE for a purification of sperms from mixture samples. Thus, we present that FM could simply lead to success of sperm-DNA genotyping and has a possibility to supersede DE as a gold-standard method.
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Affiliation(s)
- Toshifumi Nakagawa
- Forensic Science Laboratory, Ehime Prefectural Police Headquarters, 2-2 Minamihoribatacho, Matsuyama, Ehime 790-8573, Japan.
| | - Masanori Doi
- Forensic Science Laboratory, Ehime Prefectural Police Headquarters, 2-2 Minamihoribatacho, Matsuyama, Ehime 790-8573, Japan
| | - Kosuke Nishi
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Food and Health Sciences Research Center, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Takuya Sugahara
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Food and Health Sciences Research Center, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
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4
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Le TN, Handt O, Henry J, Linacre A. A novel approach for rapid cell assessment to estimate DNA recovery from human bone tissue. Forensic Sci Med Pathol 2021; 17:649-659. [PMID: 34633584 DOI: 10.1007/s12024-021-00428-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2021] [Indexed: 11/26/2022]
Abstract
We report on the use of a DNA staining dye to locate and record nucleated osteocytes and other bone-related cells within sections of archived formalin-fixed and paraffin-embedded human tibia from which informative DNA profiles were obtained. Eleven of these archived tibia samples were sectioned at a thickness of 5 µm. Diamond™ Nucleic Acid Dye was applied to the sections and cells within the matrix of the bone fluoresced so that their location and number of cells could be photographed. DNA was isolated from these 11 samples using a standard extraction process and the yields were quantified by real-time PCR. Complete STR profiles were generated from ten bone extracts where low-level inhibition was recorded with an incomplete STR profile obtained from one sample with higher inhibition. The stained image of this sample showed that few cells were present. There was a significant relationship between the number of DD-stained cells and the number of alleles obtained (p < 0.05). Staining cells to determine the prevalence of bone cell nuclei allows a triage of samples prior to any subsequent DNA profiling.
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Affiliation(s)
- Thien Ngoc Le
- College of Science and Engineering, Flinders University, Flinders, SA, 5042, Australia
| | - Oliva Handt
- College of Science and Engineering, Flinders University, Flinders, SA, 5042, Australia
- Forensic Science SA, PO Box 2790, Adelaide, SA, 5001, Australia
| | - Julianne Henry
- College of Science and Engineering, Flinders University, Flinders, SA, 5042, Australia
- Forensic Science SA, PO Box 2790, Adelaide, SA, 5001, Australia
| | - Adrian Linacre
- College of Science and Engineering, Flinders University, Flinders, SA, 5042, Australia.
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5
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Ostojic L, O'Connor C, Wurmbach E. Micromanipulation of single cells and fingerprints for forensic identification. Forensic Sci Int Genet 2020; 51:102430. [PMID: 33260060 DOI: 10.1016/j.fsigen.2020.102430] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/13/2020] [Accepted: 11/15/2020] [Indexed: 01/18/2023]
Abstract
Crime scene samples often include biological stains, handled items, or worn clothes and may contain cells from various donors. Applying routine sample collection methods by using a portion of a biological stain or swabbing the entire suspected touched area of the evidence followed by DNA extraction often leads to DNA mixtures. Some mixtures can be addressed with sophisticated interpretation protocols and probabilistic genotyping software resulting in DNA profiles of their contributors. However, many samples remain unresolved, providing no investigative information. Samples with many contributors are often the most challenging samples in forensic biology. Examples include gang rape situations or where the perpetrator's DNA is present in traces among the overwhelming amounts of the victim's DNA. If this is the only available evidence in a case, it is of paramount importance to generate usable information. An alternative approach, to address biological mixtures, could be the collection of individual cells directly from the evidence and testing them separately. This method could prevent cells from being inadvertently blended during the extraction process, thus resulting in DNA mixtures. In this study, multiple tools coupled with adhesive microcarriers to collect single cells were evaluated. These were tested on epithelial (buccal) and sperm cells, as well as on touched items. Single cells were successfully collected but fingerprints were swabbed in their entirety to account for the extracellular DNA of these samples and the poor DNA quality of shed skin flakes. Furthermore, micromanipulation devices, such as the P.A.L.M.® and the Axio Zoom.V16 operated manually or with a robotic arm aureka®, were compared for their effectiveness in collecting cells. The P.A.L.M.® was suitable for single cell isolation when smeared on membrane slides. Manual or robotic manipulations, by utilizing the Axio Zoom.V16, have wider applications as they can be used to isolate cells from various substrates such as glass or membrane slides, tapes, or directly from the evidence. Manipulations using the Axio Zoom.V16, either with the robotic arm aureka® or manually, generated similar outcomes which were significantly better than the outcomes by using the P.A.L.M.®. Robotic manipulations using the aureka® produced more consistent results, but operating the aureka® required training and often needed re-calibrations. This made the process of cell manipulations slower than when manually operated. Our preferred method was the manual manipulations as it was fast, cost effective, required little training, but relied on a steady hand of the technician.
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Affiliation(s)
- Lana Ostojic
- Department of Forensic Biology, Office of Chief Medical Examiner, New York, N.Y, 10016, USA
| | - Craig O'Connor
- Department of Forensic Biology, Office of Chief Medical Examiner, New York, N.Y, 10016, USA
| | - Elisa Wurmbach
- Department of Forensic Biology, Office of Chief Medical Examiner, New York, N.Y, 10016, USA.
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6
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England R, Nancollis G, Stacey J, Sarman A, Min J, Harbison S. Compatibility of the ForenSeq™ DNA Signature Prep Kit with laser microdissected cells: An exploration of issues that arise with samples containing low cell numbers. Forensic Sci Int Genet 2020; 47:102278. [DOI: 10.1016/j.fsigen.2020.102278] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/05/2020] [Accepted: 03/15/2020] [Indexed: 12/27/2022]
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7
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Jiang W, Lian W, Chen J, Li W, Huang J, Lai B, Li L, Huang Z, Xu J. Rapid identification of genome-edited mesenchymal stem cell colonies via Cas9. Biotechniques 2019; 66:231-234. [PMID: 30924368 DOI: 10.2144/btn-2018-0183] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Mesenchymal stem cells (MSCs) have been intensively investigated and widely applied in regenerative medicine and immune modulation. However, their efficacy declines during the aging or disease process. Thus, genome-edited MSCs with over-expression or inhibition of specific genes hold a great deal of promise in terms of their therapeutic application. Here we optimized the direct PCR approach for rapid identification of genome-edited MSCs with only ten cells required, which reduces the time and labor to expand the MSC colonies. Combined with our previously optimized guide RNA structure and plasmid construction strategy for Cas9, we successfully identified MSC colonies over-expressing IL-10 in the AAVS1 locus.
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Affiliation(s)
- Wei Jiang
- Department of Anatomy, Histology & Developmental Biology, School of Basic Medical Sciences, Shenzhen University Health Science Centre, Shenzhen, P.R. China
| | - Wei Lian
- Department of Immunology, School of Medicine, Shenzhen University, Shenzhen, P.R. China
| | - Jieting Chen
- Department of Obstetrics, People's Hospital of Baoan, Shenzhen, P.R. China
| | - Wenlei Li
- Department of Obstetrics, Women & Children Health Institute of Futian, Shenzhen, P.R. China
| | - Jieyong Huang
- Department of Immunology, School of Medicine, Shenzhen University, Shenzhen, P.R. China
| | - Baoyu Lai
- Department of Immunology, School of Medicine, Shenzhen University, Shenzhen, P.R. China
| | - Lingyun Li
- Department of Immunology, School of Medicine, Shenzhen University, Shenzhen, P.R. China
| | - Zhong Huang
- Department of Immunology, School of Medicine, Shenzhen University, Shenzhen, P.R. China
| | - Jianyong Xu
- Department of Immunology, School of Medicine, Shenzhen University, Shenzhen, P.R. China
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8
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van Oorschot RA, Szkuta B, Meakin GE, Kokshoorn B, Goray M. DNA transfer in forensic science: A review. Forensic Sci Int Genet 2019; 38:140-166. [DOI: 10.1016/j.fsigen.2018.10.014] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 02/07/2023]
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9
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Vintiner SK, Veth JS, Bright JA. A review of DNA profiling success for laser microdissected forensic casework samples. AUST J FORENSIC SCI 2018. [DOI: 10.1080/00450618.2018.1510030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- S. K. Vintiner
- Institute of Environmental Science and Research Ltd (ESR), Auckland, New Zealand
| | - J. S. Veth
- Institute of Environmental Science and Research Ltd (ESR), Auckland, New Zealand
| | - J.-A. Bright
- Institute of Environmental Science and Research Ltd (ESR), Auckland, New Zealand
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10
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Nancollis G, England R, Harbison SA. Establishing the limit of detection of massively parallel sequencing using laser micro-dissected cells. FORENSIC SCIENCE INTERNATIONAL GENETICS SUPPLEMENT SERIES 2017. [DOI: 10.1016/j.fsigss.2017.09.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Costa S, Correia-de-Sá P, Porto MJ, Cainé L. The Use of Laser Microdissection in Forensic Sexual Assault Casework: Pros and Cons Compared to Standard Methods. J Forensic Sci 2017; 62:998-1006. [DOI: 10.1111/1556-4029.13348] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/31/2016] [Accepted: 09/10/2016] [Indexed: 12/01/2022]
Affiliation(s)
- Sergio Costa
- Department of Legal Medicine and Forensic Sciences; Faculty of Medicine; University of Porto; Porto Portugal
- North Department; National Institute of Legal Medicine and Forensic Sciences; Oporto Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP); Instituto de Ciências Biomédicas de Abel Salazar (ICBAS); Universidade do Porto (UP); Porto Portugal
| | - Maria J. Porto
- North Department; National Institute of Legal Medicine and Forensic Sciences; Oporto Portugal
| | - Laura Cainé
- Department of Legal Medicine and Forensic Sciences; Faculty of Medicine; University of Porto; Porto Portugal
- North Department; National Institute of Legal Medicine and Forensic Sciences; Oporto Portugal
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12
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Hansson O, Egeland T, Gill P. Characterization of degradation and heterozygote balance by simulation of the forensic DNA analysis process. Int J Legal Med 2016; 131:303-317. [PMID: 27807625 PMCID: PMC5306348 DOI: 10.1007/s00414-016-1453-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/14/2016] [Indexed: 12/04/2022]
Abstract
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.
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Affiliation(s)
- Oskar Hansson
- Norwegian Institute of Public Health, Department of Forensic Biology, Oslo, Norway.
- Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Thore Egeland
- Norwegian Institute of Public Health, Department of Forensic Biology, Oslo, Norway
- Norwegian University of Life Sciences, Ås, Norway
| | - Peter Gill
- Norwegian Institute of Public Health, Department of Forensic Biology, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
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13
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Cotton RW, Fisher MB. Review: Properties of sperm and seminal fluid, informed by research on reproduction and contraception. Forensic Sci Int Genet 2015; 18:66-77. [DOI: 10.1016/j.fsigen.2015.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/10/2015] [Accepted: 03/12/2015] [Indexed: 12/12/2022]
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14
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Lynch L, Gamblin A, Vintiner S, Simons JL. STR profiling of epithelial cells identified by X/Y-FISH labelling and laser microdissection using standard and elevated PCR conditions. Forensic Sci Int Genet 2015; 16:1-7. [DOI: 10.1016/j.fsigen.2014.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 08/26/2014] [Accepted: 10/16/2014] [Indexed: 11/26/2022]
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15
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Han JP, Yang F, Xu C, Wei YL, Zhao XC, Hu L, Ye J, Li CX. A new strategy for sperm isolation and STR typing from multi-donor sperm mixtures. Forensic Sci Int Genet 2014; 13:239-46. [DOI: 10.1016/j.fsigen.2014.08.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/16/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022]
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16
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Hu N, Cong B, Li S, Ma C, Fu L, Zhang X. Current developments in forensic interpretation of mixed DNA samples (Review). Biomed Rep 2014; 2:309-316. [PMID: 24748965 PMCID: PMC3990198 DOI: 10.3892/br.2014.232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/22/2014] [Indexed: 11/29/2022] Open
Abstract
A number of recent improvements have provided contemporary forensic investigations with a variety of tools to improve the analysis of mixed DNA samples in criminal investigations, producing notable improvements in the analysis of complex trace samples in cases of sexual assult and homicide. Mixed DNA contains DNA from two or more contributors, compounding DNA analysis by combining DNA from one or more major contributors with small amounts of DNA from potentially numerous minor contributors. These samples are characterized by a high probability of drop-out or drop-in combined with elevated stutter, significantly increasing analysis complexity. At some loci, minor contributor alleles may be completely obscured due to amplification bias or over-amplification, creating the illusion of additional contributors. Thus, estimating the number of contributors and separating contributor genotypes at a given locus is significantly more difficult in mixed DNA samples, requiring the application of specialized protocols that have only recently been widely commercialized and standardized. Over the last decade, the accuracy and repeatability of mixed DNA analyses available to conventional forensic laboratories has greatly advanced in terms of laboratory technology, mathematical models and biostatistical software, generating more accurate, rapid and readily available data for legal proceedings and criminal cases.
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Affiliation(s)
- Na Hu
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Bin Cong
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Shujin Li
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Chunling Ma
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Lihong Fu
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Xiaojing Zhang
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
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Lounsbury JA, Nambiar SM, Karlsson A, Cunniffe H, Norris JV, Ferrance JP, Landers JP. Enhanced recovery of spermatozoa and comprehensive lysis of epithelial cells from sexual assault samples having a low cell counts or aged up to one year. Forensic Sci Int Genet 2014; 8:84-9. [DOI: 10.1016/j.fsigen.2013.06.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 05/13/2013] [Accepted: 06/30/2013] [Indexed: 11/28/2022]
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18
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Williams E, Lin MH, Harbison S, Fleming R. The development of a method of suspension RNA-FISH for forensically relevant epithelial cells using LNA probes. Forensic Sci Int Genet 2013; 9:85-92. [PMID: 24528586 DOI: 10.1016/j.fsigen.2013.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/25/2013] [Accepted: 11/28/2013] [Indexed: 11/27/2022]
Abstract
Messenger RNA profiling is becoming a common method for body fluid identification in forensic science but there are disadvantages when cell mixtures are present from more than one individual. A method that could identify and separate such cell mixtures would simplify downstream analysis. To do this, we have developed a novel method of RNA suspension-fluorescent in situ hybridization (RNA S-FISH) using a locked nucleic acid (LNA) probe for the keratin 10 (KRT10) mRNA that is suitable as a potential marker for epithelial cells. As sample size may be restricted in forensic samples, this method has focused on minimizing cell loss whilst maintaining signal strength. Furthermore, we have shown that it is possible to obtain full DNA profiles from 150 RNA S-FISH labeled cells isolated using laser microdissection.
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Affiliation(s)
- Eletra Williams
- School of Chemical Sciences, The University of Auckland, Auckland, New Zealand; ESR, Private Bag 92021, Auckland, New Zealand
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Standard 28-cycle amplification of X/Y-FISH labelled epithelial cells for DNA profiling. FORENSIC SCIENCE INTERNATIONAL GENETICS SUPPLEMENT SERIES 2013. [DOI: 10.1016/j.fsigss.2013.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Thorpe SM, Prince DV, van Oorschot RA. Comparison of extraction methods for spermatozoa recovered using laser microdissection. FORENSIC SCIENCE INTERNATIONAL GENETICS SUPPLEMENT SERIES 2011. [DOI: 10.1016/j.fsigss.2011.08.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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21
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Hopwood AJ, Elliott K. Forensic DNA research: keeping it real. Int J Legal Med 2011; 126:343-4. [PMID: 22005759 DOI: 10.1007/s00414-011-0636-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 10/07/2011] [Indexed: 11/30/2022]
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