Validation and implementation of MPS mtDNA control region analysis for forensic casework: Determination of C-stretch lengths by the FDSTools noise correction feature  K.J. van der Gaag, J. Hoogenboom, T. Sijen  Forensic Science International: Genetics Supplement Series  Volume 6, Pages e558-e559 (December 2017) DOI: 10.1016/j.fsigss.2017.09.216 Copyright © 2017 Elsevier B.V. Terms and Conditions

Fig. 1 Observed variation in C-stretch noise variants. At the left, observed C-stretch noise (n+1) is displayed for the tested reference samples before applying FDSTools correction. The curve displays the result of the fitted function. At the right, two examples are shown of typical distributions of the length variants observed for fragments with a C-stretch of 8 and 11 Cs before and after correction. Note that, prior to FDSTools correction, the 12C noise variant can outnumber the reads of the genuine 11C length. Forensic Science International: Genetics Supplement Series 2017 6, e558-e559DOI: (10.1016/j.fsigss.2017.09.216) Copyright © 2017 Elsevier B.V. Terms and Conditions

Fig. 2 FDSTools sequencing profile of an mtDNA fragment containing a stretch of 11 Cs. One fragment of an FDSTools mtDNA profile is displayed for a single source sample that contains a C-stretch of 11 Cs. In this example, the majority of the n+1 artefact is corrected (light purple) and added to the genuine allele (orange). The n-1 artefact is part of the ‘Other sequences’ since it doesn’t meet the visualisation thresholds after correction. The asterisk at the n+1 artefact is a strand bias warning since less than 25% of the reads after correction is in the reverse orientation. Forensic Science International: Genetics Supplement Series 2017 6, e558-e559DOI: (10.1016/j.fsigss.2017.09.216) Copyright © 2017 Elsevier B.V. Terms and Conditions