TrueMethyl™ kits provide quantitative, accurate and repeatable single-base resolution sequencing of the modified bases hydroxymethylcytosine (5-hmC) and methylcytosine (5-mC) in genomic DNA. This capability is attributable to the kits’ utilization of oxidative bisulfite sequencing, a chemistry-based technology that can discriminate between 5-hmC and 5-mC. TrueMethyl kits can be used with a range of common platforms, including next-generation sequencing systems, 450k methylation arrays, and targeted assays. Employing chemical oxidation can give high conversion efficiencies and reduces sequence context effects, allowing the accurate profiling of 5-hmC and 5-mC during demethylation of DNA.