STRmix™ is expert forensic software that can resolve previously unresolvable mixed DNA profiles. Developed by global leaders in the field, it uses a fully continuous approach for DNA profile interpretation, resolving complex DNA mixtures worldwide.
STRmix™ interprets complex DNA results in minutes.
STRmix™ software runs on a user's PC, without the need for high-speed computing.
STRmix™ can easily be understood and explained in court by DNA analysts.
STRmix™ is a breakthrough for forensic analysts as it can assist investigations using DNA evidence that was previously considered too complex to interpret. The software has been developed by New Zealand Crown research institute ESR, with Forensic Science South Australia (FSSA).
STRmix™ includes a function that allows the software to match mixed DNA profiles directly against a database. This is a major advance for cases where there are no suspects and there is DNA from multiple contributors in one sample.
With STRmix™ you will be able to:
Information on access to STRmix™ software by defence legal teams can be found here [PDF, 352 KB]. Copyright and disclaimer can be found here [PDF, 85 KB].
STRmix™ V2.6 is now available for purchase. Join our database for updates or contact us to request a quote.
Resolve mixed DNA profiles without reference to known contributors.
Enter contributor number range when performing a deconvolution.
Model any type of stutter observed within your STR profiling kit.
Compare reference DNA profiles to single source and mixed DNA profiles and provide a statistical weighting.
Interpret DNA profiling data generated by any autosomal STR profiling kit.
Interpret DNA profiles from a range of starting template DNA concentrations.
Use laboratory-specific settings to perform calculations suited exactly to that laboratory’s results.
Search a deconvoluted DNA profile directly against a database without the need to interpret a single source component.
Calculate multiple LRs from multiple reference inputs to a previously run deconvolution (LR Batch tool).
Perform a large number of in-silico specificity tests on a profile-by-profile basis (Hd True Tester tool).
Batch multiple deconvolutions or other STRmix™ functions (such as interpretation, LR from Previous, and Database Search) in a queue, allowing the user to run them sequentially.
Combine multiple amplifications of the same DNA extract - even when generated with different multiplexes - into one interpretation.
Accommodate data generated by protocols demonstrating increased stochastic variation and non-zero allelic drop-in rates, for example elevated PCR cycle number and enhanced CE injection methods.
Include related individuals as alternate propositions in the likelihood ratio.
Carry out familial searches against a database, searching for close relatives of contributors to mixed DNA profiles.
Generate fully configurable (and if required, retrospective) reports including a CODIS report.
Password protect default settings and kit settings.
STRmix™ has already been used for routine casework interpretation at ESR and FSSA since August 2012 and is now the Australasian standard for DNA interpretation.
In one case, a mixed DNA profile was obtained from a semen stain on a carpet at the scene of an alleged sexual assault involving two male offenders. DNA from two individuals was detected, present in approximately equal proportions (see EPG below). This profile was unsuitable for database searching using traditional DNA interpretation methods. Using STRmix™, the profile was interpreted assuming two contributors and compared against a database with over 145,000 profiles. The crime profile matched two individuals.
This case highlights how STRmix™'s database search function can provide investigative information. It can also be used to validate complex mixtures where contamination is suspected.
STRmix™ V2.6 is now available for purchase. Join our database for updates or contact us to request a quote.
STRmix™ combines biological modelling and mathematical processes to interpret a wide range of complex DNA profiles.
Using well-established statistical methods, the software builds millions of conceptual DNA profiles. It grades them against the evidential sample, finding the combinations that best explain the profile. A range of Likelihood Ratio options are provided for subsequent comparisons to reference profiles.
Using a Markov Chain Monte Carlo engine, STRmix™ models allelic and any types of stutter peak heights as well as drop-in and drop out behaviour. It does this rapidly, accessing evidential information previously out of reach with traditional methods.
STRmix™ is supported by comprehensive empirical studies with its mathematics readily accessible to DNA analysts, so results are easily explained in court.
STRmix™ has been extensively validated and has been used for casework interpretation at ESR and multiple Australian, US, and UK laboratories (first implemented in August 2012). STRmix™ has achieved Certificate of Networthiness (CoN) status on the United States Army Network.
Papers describing the biological model, mathematics, performance and validation of STRmix™ have been published:
[1] D.A. Taylor, J.-A. Bright, J. S. Buckleton, The interpretation of single source and mixed DNA profiles, Forensic Science International: Genetics. 7(5) (2013) 516-528.
[2] J.-A. Bright, D.A. Taylor, J. M. Curran, J. S. Buckleton, Developing allelic and stutter peak height models for a continuous method of DNA interpretation, Forensic Science International: Genetics. 7(2) (2013) 296-304.
[3] J.-A. Bright, D.A. Taylor, J. Curran, J.S. Buckleton, Degradation of forensic DNA profiles, Australian Journal of Forensic Sciences. 45(4) (2013) 445-449.
[4] J.-A. Bright, D.A. Taylor, J. M. Curran, J. S. Buckleton, Searching mixed DNA profiles directly against profile databases Forensic Science International: Genetics. 9 (2014) 102-110.
[5] D.A. Taylor. Using continuous DNA interpretation methods to revisit likelihood ratio behaviour. Forensic Science International: Genetics, 2014. 11: 144-153.
[6] J.-A. Bright, J.M. Curran and J.S. Buckleton, The effect of the uncertainty in the number of contributors to mixed DNA profiles on profile interpretation. Forensic Science International: Genetics, 2014. 12: 208-214.
[7] J.-A. Bright, I.W. Evett, D.A. Taylor, J.M. Curran and J.S. Buckleton, A series of recommended tests when validating probabilistic DNA profile interpretation software. Forensic Science International: Genetics, 2015. 14: 125-131.
[8] J.-A. Bright, K.E. Stevenson, J.M. Curran and J.S. Buckleton, The variability in likelihood ratios due to different mechanisms. Forensic Science International: Genetics, 2015. 14:187-190.
[9] D.A. Taylor, J.-A. Bright and J.S. Buckleton, Considering relatives when assessing the evidential strength of mixed DNA profiles. Forensic Science International: Genetics, 2014. 13: 259-263.
[10] T.W. Bille, S.M. Weitz, M.D. Coble, J.S. Buckleton and J.-A. Bright, Comparison of the performance of different models for the interpretation of low level mixed DNA profiles. Electrophoresis, 2014. 35:3125-33.
[11] D.A. Taylor, J.-A. Bright and J.S. Buckleton, The ‘factor of two’ issue in mixed DNA profiles. Journal of Theoretical Biology, 2014. 363: p. 300-306.
[12] D.A. Taylor and J.S. Buckleton, Do low template DNA profiles have useful quantitative data? Forensic Science International: Genetics, 2015. 16:13-6.
[13] D.A. Taylor, J.S. Buckleton and I. Evett, Testing likelihood ratios produced from complex DNA profiles. Forensic Science International: Genetics, 2015. 16:165-171.
[14] S.J. Cooper, C.E. McGovern, J.-A. Bright, D.A. Taylor and J.S. Buckleton, Investigating a common approach to DNA profile interpretation using probabilistic software. Forensic Science International: Genetics, 2015. 16:121-131.
[15] J.-A. Bright, D.A. Taylor, C.E. McGovern, S.J. Cooper, L.J. Russell, D.V. Abarno and J.S. Buckleton, Developmental validation of STRmix™, expert software for the interpretation of forensic DNA profiles. Forensic Science International: Genetics, 2016. 23:226-239.
[16] D.A. Taylor, J.-A. Bright, C.E. McGovern, C. Hefford, T. Kalafut, J.S. Buckleton, Validating multiplexes for use in conjunction with modern interpretation strategies. Forensic Science International: Genetics, 2016. 20:6-19.
[17] D.A. Taylor, J.S. Buckleton, J.-A. Bright, Factors affecting peak height variability for short tandem repeat data. Forensic Science International: Genetics, 2016. 21:126-133.
[18] T.R. Moretti, R.S. Just, S.C. Kehl, L.E. Willis, J.S. Buckleton, J.-A. Bright, D.A. Taylor, Internal validation of STRmix™ for the interpretation of single source and mixed DNA profiles. Forensic Science International: Genetics, 2017. 29:126-144.
[19] D.A. Taylor, J.-A. Bright, H. Kelly, M.-H. Lin, J.S. Buckleton. A fully continuous system of DNA profile evidence evaluation that can utilise STR profile data produced under different conditions within a single analysis. Forensic Science International: Genetics, 2017. 31:149-154.
[20] D.A. Taylor, J.S. Buckleton, J.-A. Bright, Does the use of probabilistic genotyping change the way we should view sub-threshold data? Australian Journal of Forensic Sciences, 2017. 49(1):78-92.
[21] J.-A. Bright, et al., Internal validation of STRmix; A multi laboratory response to PCAST. Forensic Science International: Genetics, 2018. 34:11-24.
[22] J.S. Buckleton, et al.,The Probabilistic Genotyping Software STRmix: Utility and Evidence for its Validity. Journal of Forensic Sciences, 2019. 64(2): 393-405.
[23] D.A. Taylor, J.-A. Bright , J.S. Buckleton, Interpreting forensic DNA profiling evidence without specifying the number of contributors. Forensic Science International: Genetics. 2014;13:269-80.
[24] D.A.Taylor, J.-A. Bright, J.S. Buckleton, J. Curran, An illustration of the effect of various sources of uncertainty on DNA likelihood ratio calculations. Forensic Science International: Genetics. 2014;11:56-63.
[25] J.-A. Bright, K.E. Stevenson, M.D. Coble, C.R. Hill, J.M. Curran, J.S. Buckleton, Characterising the STR locus D6S1043 and examination of its effect on stutter rates. Forensic Science International: Genetics. 2014;8:20-3.
STRmix™ is designed to run on an individual DNA analyst’s PC (either standalone or in a networked environment), without the need for high speed computing.
| Low spec1 | Medium spec2 | High spec3 |
| Intel core 2 (Quad core) processor | Intel i5, i7 2.6 GHz | Intel 2.4 GHz Xeon CPU E54 |
| 4 GB RAM | 16 GB RAM | 128 GB RAM |
| Minimum of 2 cores | Minimum of 4 cores | Minimum of 8 cores |
| 300MB free HDD space5 | 300MB free HDD space5 | 300MB free HDD space5 |
| Windows 7 or above | Windows 7 Professional 64 bit or above | Windows 7 Professional 64 bit or above |
1 will run most 1, 2 and some 3 person mixtures, particularly in low memory mode, may also run some 4 person cases
2will run most 1, 2, 3 and 4 person mixtures, particularly in low memory mode
3will run most 1,2,3,4 person mixtures (including with replicates) and 5 person mixtures (including with replicates)
4consult with NicheVision/ESR on particular models if concerned.
5this is the space required for the application itself and does not include the space required for results of STRmix™ runs.
Windows Vista 64-bit Service Pack 1, Windows 7 64-bit Service Pack 1, Windows 8.1 64-bit, Windows 10 64-bit.
STRmix™ V2.6 is now available for purchase. Join our database for updates or contact us to request a quote.
DBLR™ calculates millions of LRs in seconds.
ACCESSIBLE
DBLR™ runs on a user’s PC, without the need for high-speed computing.
DBLR™ enables you to get more value from your DNA evidence.
For a short walk-through of the functions in DBLR™ please click here:
DBLR™ uses efficient algortihms for the fast calculation of LRs.
DBLR™ has been extensively validated by the STRmix™ team based at ESR, New Zealand.
DBLR™ is designed to run on an individual DNA analyst’s PC.
Using DBLR™ we can explore the interpretation results from a DNA profile given different hypotheses. We calculate thousands of likelihood ratios and by plotting these (as can be seen in the image below) we can see the expected range for the different hypotheses. This can quickly help inform whether the profile is suitable for comparison with a person of interest or if it is suitable for entry onto a database for matching.
The following papers describe the mathematics and application of DBLR™:
[1] Slooten K. Identifying common donors in DNA mixtures, with applications to database searches. Forensic Science International: Genetics.2017;26:40-7.
[2] Kruijver M, Bright J-A, Kelly H, Buckleton J. Exploring the probative value of mixed DNA profiles. Forensic Science International: Genetics. 2019 2019;41: 1-10.
[3] Bright J-A, Taylor D, Kerr Z, Buckleton J, Kruijver M. The efficacy of DNA mixture to mixture matching. Forensic Science International: Genetics. 2019;41: 64-71.
[4] Taylor D, Rowe E, Kruijver M, Abarno D, Bright J-A, Buckleton J. Inter-sample contamination detection using mixture deconvolution comparison. Forensic Science International: Genetics. 2019: 160-167.
To to download the latest DBLR™ brochure click here
ESR uses the power of science to solve complex problems with the potential to affect the lives of all New Zealanders. It is the sole source provider of forensic services to the New Zealand Police while its comprehensive knowledge of the presence and interpretation of DNA is utilised across the country and around the world.
FSSA provides independent, objective expert scientific opinions and evidence to the justice system and community of South Australia undertaking a comprehensive range of forensic case work in Pathology, Biology, Toxicology and Chemistry.
STRmix Limited is a newly formed subsidiary of ESR, and was founded to better serve international customers of STRmix™.
STRmix™ is expert forensic software that can resolve previously unresolvable mixed DNA profiles. Developed by world leaders in the field, it uses a fully continuous approach for DNA profile interpretation, resolving complex DNA mixtures with no restriction on the number of contributors.
North/South/Central America Distributor
NicheVision Inc.
526 So Main St Ste 714-G, Akron OH 44311, USA
1-866-840-3758 (US Only) or 1-330-252-2711 (International)
Vic Meles
vic@nichevision.com
UK/Europe/ROW
Adam McCarthy
M: +44(0)7590 405 501
E: Adam.Mccarthy@esr.cri.nz
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