STRmix
Definition
A continuous probabilistic genotyping platform developed by ESR (New Zealand) and the Australian Federal Police. The most widely used PG platform in the US, UK, Australia, and New Zealand.
- Developers
- ESR (New Zealand), Forensic Science South Australia
- Category
- Continuous probabilistic genotyping software
- Widely adopted in
- US, UK, Australia, New Zealand
- Purpose
- Interprets mixed DNA profiles
Common questions
What does 'continuous' mean in continuous probabilistic genotyping?+
A continuous model uses the actual peak heights in the electropherogram directly in its statistical calculation, rather than first reducing the data to a binary list of alleles present or absent, which lets it weigh partial and low-level contributions more accurately.
How is a platform like STRmix validated before courtroom use?+
Laboratories run internal validation studies against known mixtures of varying contributor numbers and ratios, comparing the software's output to the ground truth, and results are typically reviewed against published peer-reviewed validation literature before adoption.
Related terms
- Continuous Model
- A probabilistic genotyping approach that treats peak heights as a continuous variable and models their probability under different contributor genotype combinations, as...
- EuroForMix
- An open-source continuous probabilistic genotyping platform developed by the Norwegian Institute of Public Health. Distributed as an R package and used by...
- LRmix Studio
- A semi-continuous probabilistic genotyping platform developed at Leiden University Medical Center. One of the first PG tools adopted by European forensic laboratories;...
- MCMC (Markov Chain Monte Carlo)
- A computational sampling method used by STRmix and TrueAllele to integrate the likelihood function over all possible contributor genotype combinations. Requires many...
- Mixture
- A DNA sample containing contributions from two or more individuals. Identified by the presence of more than two alleles at one or...
- Mixture Ratio
- The proportional representation of each contributor's DNA in the mixture, estimated from the relative peak heights of non-overlapping alleles across multiple loci.
- Number of Contributors (NoC)
- The estimated minimum number of individuals whose DNA is present in a mixture, derived from the maximum allele count at any single...
- Probabilistic Genotyping (PG)
- A computational approach to mixture interpretation that models the entire electropherogram as a probabilistic output of a specified number of contributors, computing...
- Stochastic Threshold (ST)
- A validated minimum peak height below which allele calls are considered uncertain due to stochastic amplification effects. Profiles with peaks between the...
- TrueAllele
- A continuous probabilistic genotyping platform developed by Cybergenetics (Pittsburgh, PA). Used primarily in US criminal courts; available as a cloud-based service.