Detection of IP3 with AlphaScreen is based on the competition between IP3 produced by cells and a biotinylated IP3 analog (b-IP3) binding to a GST-tagged IP3 binding protein (GST-IP3 -bp). The b-IP3 and GST-IP3 bp are recognized by the streptavidin-Donor and anti-GST conjugated Acceptor beads, respectively. The beads are brought into proximity and a signal is detected. Increased intracellular concentrations of IP3 following GPCR activation by an agonist results in the displacement of the b-IP3 and leads to a proportional signal decrease.
AlphaScreen™ IP3 Assay Supplement, 10,000 assay points
AlphaScreen™ IP3 Assay Supplement, 500 assay points