mixsep: An R-package for DNA mixture separation

An implementation of a mixture separating algorithm based on a statistical model for [2] STR peak intensities is presented [4]. The implementation is freely available in the open source software R. A graphical user interface (GUI) eases the data importing, specification of known profiles and analysis of the STR data [3].

The statistical model formulated for the peak intensities satisfy intrinsic proportions of the STR peak data, and assumes that the contribution to shared alleles is additive in terms of the total amount of DNA. The model and algorithm for separating DNA mixtures was validated and gave similar results as those of three experienced forensic geneticists. The advantages of the model-based approach are consistency in case reports within a laboratory, increased speed and objective measures for comparing different proposed combinations of DNA profiles. Furthermore, the statistical model can be used to compute expected peak intensities, which plotted together with the observed peak intensities provide a powerful tool for communicating the conclusions of an analysis.