PAR-CLIP

PAR -CLIP (English Photo Activatable - ribonucleosides -Enhanced Crosslinking and Immunoprecipitation, crosslinking and immunoprecipitation with photoactivatable ribonucleotides ' ) is a method for determining the biochemistry of RNA - protein interactions. Such interactions take place eg ribonucleoproteins and protein complexes containing micro- RNA.

Principle

The PAR -CLIP consists of a combination of a UV cross-linking, immunoprecipitation, a partial nucleolysis, an RT -PCR and DNA sequencing in high throughput. The PAR -CLIP uses a built-in UV reactive nucleoside analogue 4- thiouridine (4- SU) and 6- thioguanosine (6- SG) in vivo. Irradiating the cells with a wavelength of 365 nm results in an interconnection with interacting proteins. This is followed by immunoprecipitation using the well-known protein, and a RT-PCR of isolated RNA. The DNA sequences of the cDNA generated is determined by DNA sequencing.

The PAR -CLIP has similarities to the CLIP -Seq and iCLIP which do without nucleoside analogues. RIP uses a microarray chip, instead of the RT-PCR and DNA sequencing. The ChIP -Seq is used to study DNA -protein interactions and the ChIP -on-chip is used for analyzing DNA -protein interactions with a microarray instead of DNA sequencing.