Our CELT-331 product is a potent and selective hCB₂ fluorescent ligand that shows a high affinity and selectivity for hCB₂ receptor over hCB₁ receptor. It has a K_i  value of 75.9 nM for hCB₂ receptor in radioligand binding assay. CELT-331 is suitable for HTRF binding assays as a valid alternative to radioligand binding assays. It is available in a 10 µg vial that allows for the preparation of 150 mL of 100 nM working solution to test CB₂R. CELT-331 is designed to allow for cell visualization in fluorescence microscopy, confocal, and high-content system experiments and is potentially suitable for other fluorescence-based assays.