Cross-linkers are used to determine the relationship between adjacent proteins as well as ligand-receptor interactions. Photo-reactive crosslinkers are widely used for nonspecific bioconjugation. While numerous options exist, the two most common photo-reactive chemical groups are diazirines and aryl-azides. Photo cross linkers are used for the study of protein-protein or protein-oligonucleotide interactions in living cells. They are typically used in the following manner:
- Photo-cross-linkers are incorporated in the desired proteins or oligonucleotides within cells.
- Cells are exposed to UV radiation to induce the cross-linking between molecules in contact to the cross-linking functional groups.
- Following cross-linking, the target molecule of interest and its cross-linked complexes are isolated using immune-purification and analyzed using mass spectrometry.