Kelly Daggett has extensive experience with optimizing photocrosslinking strategies to probe protein-protein interactions in cells.  In the scheme depicted, the unique amino acid, p-benzoyl-L-phenylalanine (Bzp), is site-specifically incorporated into a heptahelical receptor when the amber codon (UAG) is suppressed. When irradiated with UV light, the receptor containing the Bzp will form a covalent bond with an interacting partner allowing for identification of specific interactions.