title: UMI-tools: modeling sequencing errors in Unique Molecular Identifiers to improve quantification accuracy.
abstract: Unique Molecular Identifiers (UMIs) are random oligonucleotide barcodes that are increasingly used in high-throughput sequencing experiments. Through a UMI, identical copies arising from distinct molecules can be distinguished from those arising through PCR amplification of the same molecule. However, bioinformatic methods to leverage the information from UMIs have yet to be formalized. In particular, sequencing errors in the UMI sequence are often ignored or else resolved in an ad hoc manner. We show that errors in the UMI sequence are common and introduce network-based methods to account for these errors when identifying PCR duplicates. Using these methods, we demonstrate improved quantification accuracy both under simulated conditions and real iCLIP and single-cell RNA-seq data sets. Reproducibility between iCLIP replicates and single-cell RNA-seq clustering are both improved using our proposed network-based method, demonstrating the value of properly accounting for errors in UMIs. These methods are implemented in the open source UMI-tools software package.
authors.affiliation: Computational Genomics Analysis and Training Programme, MRC WIMM Centre for Computational Biology, University of Oxford, Oxford OX3 9DS, United Kingdom.
authors.forename: Tom
authors.identifier: 0000-0002-0697-8777
authors.initials: T
authors.lastname: Smith
authors.affiliation: Computational Genomics Analysis and Training Programme, MRC WIMM Centre for Computational Biology, University of Oxford, Oxford OX3 9DS, United Kingdom.
authors.forename: Andreas
authors.identifier: 0000-0001-7720-0447
authors.initials: A
authors.lastname: Heger
authors.affiliation: Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom.
authors.forename: Ian
authors.identifier: 0000-0002-5038-0190
authors.initials: I
authors.lastname: Sudbery
mesh_terms: D006801:Humans; D017422:Sequence Analysis, DNA / Q000379:methods / Q000592:standards*; D012984:Software