Nearly 70% of GPCRs’ signals are conveyed by cyclic 3’,5’-adenosine monophosphate (cAMP) to their downstream signalling cascades. Therefore, intracellular cAMP level can serve as an indicator of the function status of GPCRs.



Enzyme Immunoassays for cAMP and cGMP offer a convenient, sensitive and accurate method to quantify cyclic-AMP and -GMP in a variety of samples such as cell and tissue lysates for format A, dried biological fluids, tissue culture media or urine for format B)



A live-cell cAMP assay has been developed to record the fluctuation of intracellular cAMP real-time. By employing a mutant cyclic-nucleotide-gated ion channel (CNG) as cAMP biosensor, the alteration of cAMP level is linked to the changes of transmembrane potential or intracellular calcium level. In current study, we have developed a new membrane potential dye and successfully applied it to this live-cell homogenous cAMP assay. This anionic oxonol-based membrane potential dye, HLB 021-152, has improved characteristics compared to the existing membrane potential dyes. The assay is in a mix-and-read format, which is readily adapted to high throughput screening of GPCR-based drugs and GPCR functional analysis.