Choosing the Right Calcium Assay Readout for Measuring GPCR Activation

G-protein coupled receptors (GPCRs) are prime targets for research and drug development, powering 30-50% of marketed therapeutics through diverse signaling mechanisms including cAMP, calcium, and β-arrestin pathways. When assaying GPCR activity, choosing the right readout is essential. Gαq/11-coupled GPCRs activate phospholipase C, producing IP3 that triggers release of calcium from the endoplasmic reticulum (ER) and elevates cytoplasmic Ca2+, a common detection point. This blog covers calcium assay principles, use cases, and trade-offs to help you select the best approach for your GPCR studies.