In a paper published online in advance in Science this week, researchers at the University of Cambridge and at the Babraham Institute in the UK present oxidative bisulfite sequencing, or oxBS-seq, which they note is "the first method for quantitative mapping of 5hmC in genomic DNA at single-nucleotide resolution." The team says the results of its work to quantify 5hmC at CpG islands in murine embryonic stem cells "open new questions on 5hmC dynamics and sequence-specific targeting