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Ansell, Ricky
Publications (10 of 93) Show all publications
Kokshoorn, B., Aarts, L. H. .., Ansell, R., Connolly, E., Drotz, W., Kloosterman, A. D., . . . Oorschot, R. A. .. (2018). Sharing data on DNA transfer, persistence, prevalence and recovery: Arguments for harmonization and standardization. Forensic Science International: Genetics, 37, 260-269
Open this publication in new window or tab >>Sharing data on DNA transfer, persistence, prevalence and recovery: Arguments for harmonization and standardization
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2018 (English)In: Forensic Science International: Genetics, ISSN 1872-4973, E-ISSN 1878-0326, Vol. 37, p. 260-269Article in journal (Refereed) Published
Abstract [en]

Sharing data between forensic scientists on DNA transfer, persistence, prevalence and recovery (TPPR) is crucial to advance the understanding of these issues in the criminal justice community. We present the results of a collaborative exercise on reporting forensic genetics findings given activity level propositions. This exercise outlined differences in the methodology that was applied by the participating laboratories, as well as limitations to the use of published data on DNA TPPR. We demonstrate how publication of experimental results in scientific journals can be further improved to allow for an adequate use of these data. Steps that can be taken to share and use these data for research and casework purposes are outlined, and the prospects for future sharing of data through publicly accessible databases are discussed. This paper also explores potential avenues to proceed with implementation and is intended to fuel the discussion on sharing data pertaining to DNA TPPR issues. It is further suggested that international standardization and harmonization on these topics will benefit the forensic DNA community as it has been achieved in the past with the harmonization of STR typing systems.

Keywords
Activity level inference, Criminalistics, Database, Data exchange, DNA transfer, DNA persistence, DNA prevalence, DNA recovery, Trace DNA, Forensic biology
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-151962 (URN)10.1016/j.fsigen.2018.09.006 (DOI)
Available from: 2018-10-11 Created: 2018-10-11 Last updated: 2018-10-11
Boiso, S., Dalin, E., Seidlitz, H., Sidstedt, M., Trygg, E., Hedman, J. & Ansell, R. (2017). RapidHIT for the purpose of stain analyses – An interrupted implementation. Forensic Science International: Genetics Supplement Series, 6(Supplement C), e589-e590
Open this publication in new window or tab >>RapidHIT for the purpose of stain analyses – An interrupted implementation
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2017 (English)In: Forensic Science International: Genetics Supplement Series, ISSN 1875-1768, E-ISSN 1875-175X, Vol. 6, no Supplement C, p. e589-e590Article in journal (Refereed) Published
Abstract [en]

Rapid DNA instruments have in recent years been developed, enabling analysis of forensic samples with a minimum of human intervention. Initially intended for fast handling of reference samples, such as samples from suspects in booking suites, attention shifted to include crime scene samples. The aim of this study was to determine whether or not the RapidHIT System (IntegenX) is fit for crime scene samples. The first runs gave very poor results, which was found to be due to an incorrect firmware setting leading to no or just minute amounts of amplicons being injected for electrophoresis. After solving this problem, 28 full runs (seven samples each) applying NGM SElect Express were performed comprising various amounts of blood on cotton swabs. Six of the runs failed completely, four due to cartridge leakage and in two runs the PCR mix was not injected. For 155 samples with 1–5ÎŒL blood (volumes for which complete DNA profiles are expected), 119 samples (77%) gave complete DNA profiles. Among the most serious failures were incorrect allele calling and leakage of DNA extract or PCR product. Other general issues were failure to export results, anode motor breakdown and broken capillary array. Due to the encountered problems with software, hardware and cartridges, together with the low success rate, it was decided not to continue towards implementation of the RapidHIT System in casework.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Automation, Forensic DNA analyses, Rapid DNA, RapidHIT System, STR
National Category
Analytical Chemistry Biomedical Laboratory Science/Technology Forensic Science
Identifiers
urn:nbn:se:liu:diva-144104 (URN)10.1016/j.fsigss.2017.10.002 (DOI)
Available from: 2018-01-05 Created: 2018-01-05 Last updated: 2018-01-05
Ansell, R. & Allen, M. (2016). DNA-analyser inom brottsbekämpningen. In: Eva Regårdh, Sofie Pehrssoon (Ed.), Skurk, sjuk eller släkt?: vem ska ha ditt DNA? (pp. 18-27). Stockholm: Stiftelsen för strategisk forskning
Open this publication in new window or tab >>DNA-analyser inom brottsbekämpningen
2016 (Swedish)In: Skurk, sjuk eller släkt?: vem ska ha ditt DNA? / [ed] Eva Regårdh, Sofie Pehrssoon, Stockholm: Stiftelsen för strategisk forskning , 2016, p. 18-27Chapter in book (Other academic)
Abstract [sv]

Idag räcker det med DNA från enstaka celler för att kunna få fram en DNA-profil som kan jämföras med per-soner eller andra DNA-spår. En DNA-träff mot ett biologiskt spår kan utgöra en mycket stark bevisning och vara avgörande för en fällande dom. DNA-teknik gör det möjligt att analysera och ta fram en DNA-profil för de allra flesta typer av humana biologiska spår som avsatts i samband med brott, såsom blod, sperma, vaginalsekret, saliv, hår och ”kontaktspår”. Teknikerna har med åren utvecklats och förfinats. På senare år har också det internationella utbytet av DNA-profiler ökat samtidigt som fortsatt teknik- och metodutveckling banar väg för fördjupade analy-ser som kan bidra till att klara upp brott. Det kan handla om att utifrån DNA-spår ringa in ungefärlig ålder, ursprung, hårfärg, ögonfärg och kroppsstorlek på en misstänkt gärningsman

Place, publisher, year, edition, pages
Stockholm: Stiftelsen för strategisk forskning, 2016
Series
SSF-rapport, ISSN 1654-9872 ; 24
Keywords
Humant genom, DNA, Kriminalteknik
National Category
Biophysics
Identifiers
urn:nbn:se:liu:diva-130505 (URN)9189206657 (ISBN)9789189206656 (ISBN)
Available from: 2016-08-11 Created: 2016-08-11 Last updated: 2016-09-15Bibliographically approved
Foreberg, C., Jansson, L., Ansell, R. & Hedman, J. (2016). High-throughput DNA extraction of forensic adhesive tapes. Forensic Science International: Genetics, 24, 158-163
Open this publication in new window or tab >>High-throughput DNA extraction of forensic adhesive tapes
2016 (English)In: Forensic Science International: Genetics, ISSN 1872-4973, E-ISSN 1878-0326, Vol. 24, p. 158-163Article in journal (Refereed) Published
Abstract [en]

Tape-lifting has since its introduction in the early 2000's become a well-established sampling method in forensic DNA analysis. Sampling is quick and straightforward while the following DNA extraction is more challenging due to the "stickiness", rigidity and size of the tape. We have developed, validated and implemented a simple and efficient direct lysis DNA extraction protocol for adhesive tapes that requires limited manual labour. The method uses Chelex beads and is applied with SceneSafe FAST tape. This direct lysis protocol provided higher mean DNA yields than PrepFiler Express BTA on Automate Express, although the differences were not significant when using clothes worn in a controlled fashion as reference material (p=0.13 and p=0.34 for T-shirts and button-down shirts, respectively). Through in-house validation we show that the method is fit-for-purpose for application in casework, as it provides high DNA yields and amplifiability, as well as good reproducibility and DNA extract stability. After implementation in casework, the proportion of extracts with DNA concentrations above 0.01ng/μL increased from 71% to 76%. Apart from providing higher DNA yields compared with the previous method, the introduction of the developed direct lysis protocol also reduced the amount of manual labour by half and doubled the potential throughput for tapes at the laboratory. Generally, simplified manual protocols can serve as a cost-effective alternative to sophisticated automation solutions when the aim is to enable high-throughput DNA extraction of complex crime scene samples.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Forensic biology, Forensic DNA analysis, High-throughput, Tape-lifting, Trace sampling, Touch DNA
National Category
Genetics
Identifiers
urn:nbn:se:liu:diva-130503 (URN)10.1016/j.fsigen.2016.06.004 (DOI)000381730400029 ()27448236 (PubMedID)
Note

Funding agencies: Swedish Civil Contingencies Agency (MSB)

Available from: 2016-08-11 Created: 2016-08-11 Last updated: 2017-11-28
Ansell, R. & Widén, C. (2016). Swedish Legislation Regarding Forensic DNA Elimination Databases. Forensic Science Policy & Management: An International Journal , 7(1-2), 20-36
Open this publication in new window or tab >>Swedish Legislation Regarding Forensic DNA Elimination Databases
2016 (English)In: Forensic Science Policy & Management: An International Journal , ISSN 1940-9044, Vol. 7, no 1-2, p. 20-36Article in journal (Refereed) Published
Abstract [en]

Evidence contaminated with DNA from staff, police, and other individuals can have a dramaticimpact on an investigation and can mislead police inquiries. Forensic DNA elimination databases(EDB) are used to minimize the risks associated with DNA contamination. Central issues withmaintaining such databases include the basis for sample collection, sample, and profile integrity, aswell as retention times, database access, and procedures when a database match occurs. Followingyears of discussion, debate, and the use of an “in house” EDB at the Swedish National ForensicCentre (NFC), these issues have now been resolved by passing legislation on DNA EDB. According tothe legislation, sampling for EDB purposes is mandatory for certain forensic professionals, as well asfor other individuals who need access to the premises handling DNA evidence. In the event of adatabase match, the match can only be reviewed and evaluated for quality purposes and the nameof the donor cannot be disclosed to the crime inquiry. Thus, as a consequence, if a contaminationevent is not the probable cause the legal limitation opens for impunity for individuals included inthe database.KEYWORDSContamination; DNA;elimination database;forensic science; legislationIntroduction

Place, publisher, year, edition, pages
Taylor & Francis Group, 2016
Keywords
Contamination, DNA, elimination database, forensic science, legislation
National Category
Forensic Science
Identifiers
urn:nbn:se:liu:diva-130593 (URN)10.1080/19409044.2015.1099061 (DOI)
Available from: 2016-08-17 Created: 2016-08-17 Last updated: 2016-08-24
Sanga, M., Norén, L., Lindsten, H., Rådström, P., Ansell, R. & Hedman, J. (2015). A panel of PCR-inhibitory reference materials for quality evaluation of multiplex STR analysis kits: -. In: Abstracts ISFG: . Paper presented at 26th Congress of the International Society for Forensic Genetics (pp. 226).
Open this publication in new window or tab >>A panel of PCR-inhibitory reference materials for quality evaluation of multiplex STR analysis kits: -
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2015 (English)In: Abstracts ISFG, 2015, p. 226-Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

PCR inhibition is a key challenge in forensic DNA analysis. Substances interfering with the amplification of PCR products can lower the success rate of Short Tandem Repeat (STR) analysis or generate ambiguous DNA profiles.

For forensic DNA laboratories it is therefore vital to have knowledge about how common inhibitory substances affect their STR analysis system. We have developed a broad-range panel of standardized PCR-inhibitory reference materials (RMs), representing the heterogeneous stains found at crime scenes. The panel, including solutions prepared from for example cigarette paper,

chewing gum, moist snuff and humic acid, is a tool for quality evaluation of STR systems. We applied the RMs to challenge PowerPlex® ESX 16 Fast System (ESX Fast). Although ESX Fast tolerated high levels of some inhibitors, several RMs caused problems in different ways. Humic acid had a specific negative effect on amelogenin amplification, moist snuff hindered amplification of longer fragments, and chewing gum caused generally lowered allele peak heights. These different effects may provide information regarding the mechanisms of inhibition. For instance, our results indicate that one effect of humic acid on ESX Fast analysis is chelation of Mg2+ ions, thus altering the melting temperatures of the primers. In the developmental validation of STR systems, a limited evaluation of PCR inhibition involving only a few substances is generally performed. Applying a broad panel of RMs will ensure that a wider range of inhibitory substances from crime scene samples are included, giving a better understanding of inhibitor tolerance and effects.

 

National Category
Analytical Chemistry
Identifiers
urn:nbn:se:liu:diva-120901 (URN)
Conference
26th Congress of the International Society for Forensic Genetics
Available from: 2015-08-28 Created: 2015-08-28 Last updated: 2015-09-17
Sanga, M., Boiso, L., Lindsten, H., Rådström, P., Ansell, R. & Hedman, J. (2015). A panel of PCR-inhibitory reference materials for quality evaluation of multiplex STR analysis kits. Forensic Science International: Genetics Supplement Series, 5, e317-319
Open this publication in new window or tab >>A panel of PCR-inhibitory reference materials for quality evaluation of multiplex STR analysis kits
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2015 (English)In: Forensic Science International: Genetics Supplement Series, ISSN 1875-1768, E-ISSN 1875-175X, Vol. 5, p. e317-319Article in journal (Refereed) Published
Abstract [en]

PCR inhibition is a critical parameter in forensic DNA analysis. Substances interfering with amplification of short tandem repeats (STRs) may generate partial and/or ambiguous DNA profiles. We present a strategy for developing a broad panel of PCR-inhibitory reference materials (RMs), representing common casework samples. Our panel, including solutions prepared from for example cigarettes, chewing gum and soil, is a tool for in-house validation and lot testing of STR systems. PowerPlex ESX 16 Fast System tolerated high levels of some RMs, but several substances caused amplification problems. Humic acid had a negative effect on amelogenin, moist snuff hindered amplification of longer fragments, and chewing gum caused generally lowered allele peak heights. Applying a broad panel of RMs ensures that a wide range of inhibitory substances are tested, giving an improved understanding of inhibitor tolerance and effects.

Place, publisher, year, edition, pages
Elsevier, 2015
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:liu:diva-123670 (URN)10.1016/j.fsigss.2015.09.126 (DOI)
Available from: 2016-01-07 Created: 2016-01-07 Last updated: 2017-12-01Bibliographically approved
Hedman, J., Ågren, J. & Ansell, R. (2015). Crime scene DNA sampling by wet-vacuum applying M-VAC: -. In: Abstracts ISFG: . Paper presented at 26th Congress of the International Society for Forensic Genetics (pp. 317).
Open this publication in new window or tab >>Crime scene DNA sampling by wet-vacuum applying M-VAC: -
2015 (English)In: Abstracts ISFG, 2015, p. 317-Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Swabs provide efficient sampling of crime scene stains from surfaces and items for subsequent forensic DNA analysis. However, swabs are not optimal for large dilute stains or absorbing materials such as fabrics. Tape-lifting works well for fabrics, but is not ideal for dried stains. A possible sampling alternative is the M-Vac wet-vacuum instrument (M-Vac Systems Inc.). We have evaluated the M-Vac for sampling of dried stains on inert surfaces and fabrics. M-Vac gave significantly higher DNA concentrations from dried saliva stains on laminated wood, compared with cotton swabs (mean DNA concentrations 1.14 and 0.57 ng/μL, respectively, p=0.02). On glass, M-Vac and cotton swabs gave similar DNA concentrations. Additionally, M-Vac retrieved over twice as much DNA from saliva stains on cotton fabric (T-shirt) compared with towels (terry-cloth), showing that the absorption properties of the surface affect wet-vacuum sampling. M-Vac was also applied for retrieving wearer DNA from clothes, enabling generation of complete DNA profiles from denim jeans, leggings and cotton T-shirt. Partial DNA profiles were retrieved from an “offender” pressing his hand against the shoulder of a person wearing a T-shirt. There, the major parts of the resulting mixed DNA profiles were from the wearer/”victim”, indicating that M-Vac may not be ideal for sampling of touch DNA from clothes. Wet-vacuum sampling requires a fairly large instrument, trained users and DNA extraction procedures handling large sample volumes. Still, in especially important cases, wet-vacuum could enable sampling of large dried stains that may be difficult to sample with other procedures.

National Category
Analytical Chemistry
Identifiers
urn:nbn:se:liu:diva-120900 (URN)
Conference
26th Congress of the International Society for Forensic Genetics
Available from: 2015-08-28 Created: 2015-08-28 Last updated: 2015-09-17
Hedman, J., Ågren, J. & Ansell, R. (2015). Crime scene DNA sampling by wet-vacuum applying M-VAC. Forensic Science International: Genetics Supplement Series, 5, e89-e90
Open this publication in new window or tab >>Crime scene DNA sampling by wet-vacuum applying M-VAC
2015 (English)In: Forensic Science International: Genetics Supplement Series, ISSN 1875-1768, E-ISSN 1875-175X, Vol. 5, p. e89-e90Article in journal (Refereed) Published
Abstract [en]

A possible alternative to conventional stain recovery by swabbing, taping or cutting, is the M-Vac wet-vacuum instrument (M-Vac Systems Inc.). We have evaluated M-Vac for sampling of dried saliva on porous and non-porous surfaces, shed cells on clothes and touch DNA. M-Vac gave significantly higher DNA yields for dried saliva stains on laminated wood, compared with cotton swabs (average DNA concentrations 1.14 vs. 0.57 ng/μL, p = 0.02). For stains on glass, M-Vac and cotton swabs gave comparable DNA yields. Additionally, M-Vac retrieved three times as much DNA from saliva stains on cotton fabric (T-shirt) compared with saliva on towels (terry cloth), showing that the absorption properties of the surface affect wet-vacuum sampling. M-Vac was also applied for retrieving wearer DNA from clothes, enabling generation of complete DNA profiles from denim jeans, leggings and cotton T-shirt. A mixed DNA profile was retrieved from an “aggressor” pressing a hand against the shoulder area of a worn T-shirt. Since the major component of the obtained mixed DNA profile was from the wearer, M-Vac may not be ideal for touch DNA sampling of clothes. Wet-vacuum sampling requires a fairly large instrument, trained users and DNA extraction procedures handling large sample volumes. The complexity of M-Vac sampling prevents it from being extensively used, but in specific and important cases it can be a valuable sampling tool.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
Cotton swab, Forensic DNA analysis, Saliva, Touch DNA
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:liu:diva-123671 (URN)10.1016/j.fsigss.2015.09.036 (DOI)
Available from: 2016-01-07 Created: 2016-01-07 Last updated: 2017-12-01Bibliographically approved
Aarts, B., Kokshoorn, B., Mc Kenna, L., Drotz, W., Ansell, R., van Oorschot, R. & Kloosterman, A. (2015). DNActivity: International cooperation in activity level interpretation of forensic DNA evidence.. In: Abstract book, 7th European Academy of Forensic Science, EAFS, Prag, Tjeckien, 2015.: . Paper presented at 7th European Academy of Forensic Science, EAFS 2015, Prague, Czech Republic, 6-11 September 2015 (pp. 555).
Open this publication in new window or tab >>DNActivity: International cooperation in activity level interpretation of forensic DNA evidence.
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2015 (English)In: Abstract book, 7th European Academy of Forensic Science, EAFS, Prag, Tjeckien, 2015., 2015, p. 555-Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Questions posed to expert witnesses by the legal community and the courts are expanding to include not just those relating to source level (i.e. ‘who is the donor of the trace?’) but also those relating to activitity level (i.e. ‘how did the DNA get there?’). The answers to these questions are usually formulated as the probability of the evidence under alternative scenarios. As activity level questions are part of investigative and legal considerations it is of paramount importance that expert witnesses are provided with knowledge and tools to address these questions.

To answer such questions within a probabilistic framework, empirical data is needed to estimate probabilities of transfer, persistence and recovery of DNA as well as background levels of DNA on everyday objects. There is a paucity of empirical data on these topics, but the number of studies is increasing both through in-house experiments and experimental data published in international scientific journals.

Laboratories that conduct such studies all use different experimental setups, trace recovery strategies and techniques and DNA analysis systems and equipment. It is essential for the forensic genetics community in general to establish whether the data generated by different labs are in concordance, and can therefore be readily used by the forensic community.

Moreover, if existing data and data generated from future experiments are made available to the (forensic) community, knowledge is needed on the key factors that underlie potential interlaboratory variation.

The aims and objectives of this ENFSI Monopoly 2013 project are to conduct a study of methodologies and data from different laboratories and to assess the comparability of the scientific data on transfer, persistence and recovery of DNA. This comparison will allow us to identify key factors that underlie potential variation. This information will be used to setup guidelines to enable sharing and database-storage of relevant scientific

data. This will improve the ability of forensic scientists and other professionals of the Criminal Justice System to give evidence-based answers to questions that relate to the activity level of the crime under investigation.

National Category
Forensic Science
Identifiers
urn:nbn:se:liu:diva-121348 (URN)
Conference
7th European Academy of Forensic Science, EAFS 2015, Prague, Czech Republic, 6-11 September 2015
Note

This project is funded by the European Union TVEFS-2020 program.

Available from: 2015-09-14 Created: 2015-09-14 Last updated: 2015-10-01Bibliographically approved
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