Ultraviolet Crosslinking of DNA-Protein Complexes via 8-Azidoadenine

In biological systems, photoreactive derivatives have been widely applied to study specific interactions of receptor molecules with their ligands by photoaffinity labeling (1 –3 ). While the receptors are generally proteins (e.g., enzymes, immunoglobulins, or hormone receptors), the ligands differ widely in their molecular structure (e.g., sugars, amino acids, nucleotides, or oligomers of these compounds).