Mapping long noncoding RNA chromatin occupancy using capture hybridization analysis of RNA targets (CHART)

Capture Hybridization Analysis of RNA Targets (CHART) has recently been developed to map the genome-wide binding profile of chromatin-associated RNAs. This protocol uses a small number of 22-28 nucleotide biotinylated antisense oligonucleotides, complementary to regions of the target RNA that are accessible for hybridization, to purify RNAs from a cross-linked chromatin extract. RNA-chromatin complexes are next immobilized on beads, washed, and specifically eluted using RNase H. Associated genomic DNA is then sequenced using high-throughput sequencing technologies and mapped to the genome to identify RNA-chromatin associations on a large scale. CHART-based strategies can be applied to determine the nature and extent of long noncoding RNA (long ncRNA) association with chromatin genome-wide and identify direct long ncRNA transcriptional targets.