FAQ

What is LRmix Studio?
LRmix Studio is an expert system dedicated to the interpretation of forensic DNA profiles, with a particular focus on complex DNA mixtures. LRmix Studio is programmed after the likelihood ratio model described in Haned et al (FSIG 2012) and Gill & Haned (FSIG 2013).
LRmix Studio is the successor to LRmix. Both programs are free of charge and open-source, and they implement the same model (see Manual for details), however LRmix Studio is a more flexible, faster version of LRmix. It has a user-friendly interface, and offers casework friendly features such as profile visualization, and automatic report generation in PDF format. Please visit the Tutorial section. ‎

Who developed LRmix Studio?
LRmix Studio was designed and developed by Hinda Haned and Jeroen de Jong, at the Netherlands Forensic Institute. The development of this software was partly supported by a grant from the Netherlands Genomics Initiative/Netherlands Organization for Scientific Research (NWO) within the framework of the Forensic Genomics Consortium Netherlands.

What is the file format for LRmix Studio?
LRmix Studio can read files in LRmix and Genemapper® IDX formats (with or without peak heights). The provided case example contains the LRmix format only. An example allele frequencies file is also provided, please visit the Tutorial section.

Was LRmix Studio validated?
The software has been extensively checked and verified, and it was shown to yield the expected results. The same results are obtained with LRmix and LRmix Studio. LRmix Studio can be used to compare any number of replicates obtained from a specific DNA sample, to any number of reference profiles. However the software has been thoroughly tested and validated for at most five contributors. Please contact Hinda Haned for more information about validation.

LRmix Studio is open-source, is it reliable?
LRmix Studio latest stable version, developed and validated by Hinda Haned and Jeroen de Jong (NFI), is only distributed on this website, only the developers of the software can change the code of the software that is distributed here. The open-source license of the software guarantees that the methods used in the software are open and transparent to all users, this means that all users are free to change the code of the software to fit particular needs in their laboratories, however, the version distributed on this website is the only reference for the software. Modifications that are carried out independently by other users do not affect the version distributed on this website in any way. We encourage other users to send us their suggestions and comments, in the event where their suggested modifications contribute to improving the software, we would change the software accordingly.

Why is the computing time longer for marker SE33?
SE33 is a very polymorphic locus and it has more genetic variants than other STR loci. This means that when there are unknown donors in the hypotheses evaluated by the software, larger numbers of genotypic combinations have to be evaluated for SE33, than for other loci. As a consequence, computing times are longer for this locus especially if complex hypotheses are being evaluated. To help manage these computations, LRmix Studio displays a progress bar along with the expected computing times.

What does “number of threads” mean?
LRmix Studio relies on parallel processing, and the number of threads is the number of processors the program uses to run the computations. This number is automatically detected, for example, if this number is two (depending on the computer), this means that you can spread the calculations on the two processors of the computer. If you don’t limit the number of threads, this means that all of  your computer’s power will be used by LRmix Studio, and if you are using other software such as Word, then these might be slow to respond. In summary, if you are only running LRmix Studio, don’t do anything, if you are using your computer for LRmix  Studio and other programs, reduce the number of threads by one, so that LRmix Studio runs in the background.