Evaluation of ArmedXpert software tools, MixtureAce and Mixture Interpretation, to analyze MPS-STR data.

Massively parallel sequencing (MPS) technologies have revolutionized studies of genomic variations and transformed DNA analysis in multiple fields. Assays based on MPS must be capable of discriminating variations introduced by the method, i.e.

Levenshtein distance as a measure of accuracy and precision in forensic PCR-MPS methods.

Accuracy and precision determinations are standard components of method validations where they help to describe the performance of methods. Despite their importance, a standard approach to calculating these parameters is not available for the DNA sequence property of samples in forensic PCR-MPS methods. DNA sequence is a nominal property lacking magnitude and therefore standard approaches to expressing accuracy and precision do not apply.

Match statistics for sequence-based alleles in profiles from forensic PCR-mps kits.

The first autosomal sequence-based allele (aka SNP-STR haplotype) frequency database for forensic massively parallel sequencing (MPS) has been published, thereby removing one of the remaining barriers to implementing MPS in casework. The database was developed using a specific set of flank trim sites. If different trim sites or different kits with different primers are used for casework, then SNP-STR haplotypes may be detected that do not have frequencies in the database.

A nomenclature for sequence-based forensic DNA analysis.

Forensic DNA analysis of casework samples using massively parallel sequencing (MPS) technology requires a system of nomenclature for uniquely labeling sequence-based alleles and artifacts. The DNA Commission of the ISFG has published considerations concerning a nomenclature format that addresses the requirement for unique labeling of sequences. Nomenclatures based on this format can be used in databasing, or communicating sequence types, but the format is lengthy for software interfaces.

Implementation and validation of an improved allele specific stutter filtering method for electropherogram interpretation.

Modern probabilistic genotyping (PG) software is capable of modeling stutter as part of the profile weighting statistic. This allows for peaks in stutter positions to be considered as allelic or stutter or both. However, prior to running any sample through a PG calculator, the examiner must first interpret the sample, considering such things as artifacts and number of contributors (NOC or N).

A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis.

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR.