A 5-Formylcytosine-Selective Chemical Labeling

In demethylation pathways, the TET family of proteins oxidize 5mC to 5hmC, 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) in a stepwise fashion. Conversely, in vivo, 5fmC residues can be converted to cytosine by base-excision repair.In fC-Seal, 5hmC residues in the genome are blocked with regular glucose using _GT, and 5fC residues are reduced to 5hmC by NaBH4. The newly generated 5hmC residues are modified, enriched, and sequenced (Song et al., 2013)


  • Does not require antibodies


  • Cannot map 5fC and 5caC at single-nucleotide resolution and determine their relative abundance (Neri et al., 2016)


Illumina Library prep and Array Kit Selector


Neri F., Incarnato D., Krepelova A., Parlato C. and Oliviero S. Methylation-assisted bisulfite sequencing to simultaneously map 5fC and 5caC on a genome-wide scale for DNA demethylation analysis. Nat Protoc. 2016;11:1191-1205

Plongthongkum N., Diep D. H. and Zhang K. Advances in the profiling of DNA modifications: cytosine methylation and beyond. Nat Rev Genet. 2014;15:647-661


Song C. X., Szulwach K. E., Dai Q., et al. Genome-wide profiling of 5-formylcytosine reveals its roles in epigenetic priming. Cell. 2013;153:678-691