GRAB(rDA1m) is a genetically encoded red fluorescent sensor for dopamine that can be used for real-time detection of endogenous dopamine dynamics. It is a G-protein-coupled receptor activation-based ('GRAB') sensor based on the dopamine receptor encoded by the Homo sapiens DRD2 gene (HGNC:3023); a circularly permuted form of mApple has been inserted into the third intracellular loop of the DRD2 receptor, and a number of additional mutations have also been introduced during optimization of the sensor (FBrf0247852).