This detailed volume explores non-canonical amino acids (ncAAs) through their site-specific incorporation by genetic code expansion (GCE). The collection provides a broad resource of methods for implementing GCE in E. coli, mammalian cells, and animals, highlighting specific applications ranging from fluorescence labeling to photocontrol and the study of protein post-translational modification. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step and readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls.