RT Journal Article SR Electronic T1 Removing unwanted variation in a differential methylation analysis of Illumina HumanMethylation450 array data JF bioRxiv FD Cold Spring Harbor Laboratory SP 019042 DO 10.1101/019042 A1 Jovana Maksimovic A1 Johann A. Gagnon-Bartsch A1 Terence P. Speed A1 Alicia Oshlack YR 2015 UL http://biorxiv.org/content/early/2015/05/07/019042.abstract AB Due to their relatively low-cost per sample and broad, gene-centric coverage of CpGs across the human genome, Illumina’s 450k arrays are widely used in large scale differential methylation studies. However, by their very nature, large studies are particularly susceptible to the effects of unwanted variation. The effects of unwanted variation have been extensively documented in gene expression array studies and numerous methods have been developed to mitigate these effects. However, there has been much less research focused on the appropriate methodology to use for accounting for unwanted variation in methylation array studies. Here we present a novel 2-stage approach using RUV-inverse in a differential methylation analysis of 450k data and show that it outperforms existing methods.