PT - JOURNAL ARTICLE AU - Daniel Mapleson AU - Gonzalo Garcia Accinelli AU - George Kettleborough AU - Jonathan Wright AU - Bernardo J. Clavijo TI - KAT: A K-mer Analysis Toolkit to quality control NGS datasets and genome assemblies AID - 10.1101/064733 DP - 2016 Jan 01 TA - bioRxiv PG - 064733 4099 - http://biorxiv.org/content/early/2016/10/07/064733.short 4100 - http://biorxiv.org/content/early/2016/10/07/064733.full AB - Motivation De novo assembly of whole genome shotgun (WGS) next-generation sequencing (NGS) data benefits from high-quality input with high coverage. However, in practice, determining the quality and quantity of useful reads quickly and in a reference-free manner is not trivial. Gaining a better understanding of the WGS data, and how that data is utilised by assemblers, provides useful insights that can inform the assembly process and result in better assemblies.Results We present the K-mer Analysis Toolkit (KAT): a multi-purpose software toolkit for reference-free quality control (QC) of WGS reads and de novo genome assemblies, primarily via their k-mer frequencies and GC composition. KAT enables users to assess levels of errors, bias and contamination at various stages of the assembly process. In this paper we highlight KAT’s ability to provide valuable insights into assembly composition and quality of genome assemblies through pairwise comparison of k-mers present in both input reads and the assemblies.Availability KAT is available under the GPLv3 license at: https://github.com/TGAC/KAT.Contact bernardo.clavijo{at}earlham.ac.ukSupplementary Information Supplementary Information (SI) is available at Bioinformatics online. In addition, the software documentation is available online at: http://kat.readthedocs.io/en/latest/.