cross-linking study nucleic acid uv cross-linking assay MI:0430 nucl ac uv crosslink PSI-MI Nucleic acids are incubated with purified proteins or a protein mixture and then exposed to a chemical cross-linking agent that may be activated by UV light exposure. The eventual complexes can be identified by sequencing or autoradiography if the nucleic acid is radio-labelled and the sequence is known. The proteins involved in the complex can be recognized by specific antibodies or by retrieving the original protein mixture and carrying further analysis on it.