Figure 4.

Uses of fluorescent ligands to study GPCR pharmacology in vitro at endogenously levels of expression and in vivo. in vitro uses shown in (a) include using fluorescence correlation spectroscopy to measure receptor dynamics of an endogenously expressed GPCR labelled with a fluorescent ligand. This continues with using CRISPR/Cas9 to genetically modify the GPCR with NanoLuc to perform NanoBRET binding studies. In (b) human, tumour cells stably transfected with NanoLuc‐tagged GPCRs were implanted into immune‐compromised mice as a xenograft. NanoBRET binding studies were performed to monitor fluorescent ligand binding to these GPCRs in vivo