FAIRE (Formaldehyde-Assisted Isolation of Regulatory Elements) isolates active regulatory elements from human chromatin

PG Giresi, J Kim, RM McDaniell, VR Iyer… - Genome …, 2007 - genome.cshlp.org
PG Giresi, J Kim, RM McDaniell, VR Iyer, JD Lieb
Genome research, 2007genome.cshlp.org
DNA segments that actively regulate transcription in vivo are typically characterized by
eviction of nucleosomes from chromatin and are experimentally identified by their
hypersensitivity to nucleases. Here we demonstrate a simple procedure for the isolation of
nucleosome-depleted DNA from human chromatin, termed FAIRE (F ormaldehyde-A ssisted
I solation of R egulatory E lements). To perform FAIRE, chromatin is crosslinked with
formaldehyde in vivo, sheared by sonication, and phenol-chloroform extracted. The DNA …
DNA segments that actively regulate transcription in vivo are typically characterized by eviction of nucleosomes from chromatin and are experimentally identified by their hypersensitivity to nucleases. Here we demonstrate a simple procedure for the isolation of nucleosome-depleted DNA from human chromatin, termed FAIRE (Formaldehyde-Assisted Isolation of Regulatory Elements). To perform FAIRE, chromatin is crosslinked with formaldehyde in vivo, sheared by sonication, and phenol-chloroform extracted. The DNA recovered in the aqueous phase is fluorescently labeled and hybridized to a DNA microarray. FAIRE performed in human cells strongly enriches DNA coincident with the location of DNaseI hypersensitive sites, transcriptional start sites, and active promoters. Evidence for cell-type–specific patterns of FAIRE enrichment is also presented. FAIRE has utility as a positive selection for genomic regions associated with regulatory activity, including regions traditionally detected by nuclease hypersensitivity assays.
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