GRAB(sNPF1.0) is a genetically encoded sensor for short neuropeptide F (sNPF) that can be used for measurement of spatiotemporal sNPF dynamics in vivo. It is a G-protein-coupled receptor activation-based ('GRAB') sensor based on the short neuropeptide F receptor encoded by the Culex quinquefasciatus sNPFR gene; the third intracellular loop has been replaced by sequence encoding a circularly permuted form of EGFP (cpEGFP) flanked on both sides by linker sequence, and a number of additional mutations have also been introduced during optimization of the sensor. Upon binding of sNPF, conformational changes in the receptor result in a change in fluorescence of the conformationally sensitive cpEGFP (PMID:39827209).