BCIT Forensic DNA Lab
Our laboratory has incorporated STRmix™, expert forensic software developed by ESR and FSSA, that that allows us to resolve previously unresolvable mixed DNA profiles. We can now deconvolute up to four person complex mixture samples, giving us the ability to resolve samples historically too complex to interpret.
Mixture deconvolution has traditionally used a binary approach, using peak heights and mixture proportions to determine a range of possible contributors to a mixture. This means that a genotype combination was either included or excluded in a mixture analysis. This approach has challenges separating contributors when mixtures start to have close to even mixture proportions, and breaks down entirely when more than two individuals are in the mixture. Probabilistic genotyping applies an entirely different approach to mixture deconvolution; it determines the weights of all possible genotypes at each marker in a mixed profile and assesses the likelihood of each of those genotypes in a mixed profile, allowing for a more flexible approach to mixture interpretation.
Since integrating the STRmix™ deconvolution software, our laboratory has been able to assist in both longstanding unsolved and current casework that were otherwise considered exhausted using traditional interpretation approaches in alternative forensic DNA laboratories.
If you have DNA evidence that you think might benefit from STRmix™ interpretation contact our laboratory personnel and we can provide additional information to determine if this method could aid your investigation.