Chemical and Synthetic Biology Approaches To Understand Cellular Functions - Part B, Volume 622, the latest release in the Methods in Enzymology series, highlights new advances in the field, with this new volume presenting chapters that cover the Design of optogenetic proteins, the Application of optogenetic proteins, Antibody aggregation mechanism probed by a fluorescently-labeled antibody with fluorescence correlation spectroscopy, Bimane labeling of B-arrestins to measure their interaction with GPCRs, Reversible biotinylation of proteins for investigating their interaction with partners, Chemical biology approaches to study RNA cytidine acetylation, Salt sensitive intein in robotic production of peptides, and much more.