question: What is the principle of the PAR-CLIP methodology?
answer: In particular, PAR-CLIP utilizes a photoactivatable nucleoside for more efficient crosslinking.  A recent method, PAR-CLIP, uses photoreactive nucleosides to crosslink RBPs to target RNAs in cells prior to immunoprecipitation.  One characteristic feature of cDNA libraries prepared by PAR-CliP is that the precise position of crosslinking can be identified by mutations residing in the sequenced cDNA.   