Saranga Naganathan developed a novel method for site-specific antibody epitope tagging of GPCRs expressed in plasma membrane preparations (top panel) and live cells in culture (bottom panel) using Staudinger-Bertozzi chemistry.  The unnatural amino acid, p-azido-L-phenylalanine (azF), is genetically encoded and introduced using amber codon suppression technology. The antibody epitope linked to the azF is a FLAG peptide depicted as a blue oval. In-culture, epitope tagging is measured by a high-throughput whole cell-based ELISA assay (bottom panel).