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GPCR Biology

G-Protein Coupled Receptors (GPCRs) are one of the largest receptor families in the genome and are essential for the healthy function of nearly every organ in the body. GPCRs are also important targets for therapeutic drugs. Increase your understanding of drug effects and GPCR biology with bright fluorescent assays in living cells.

With our GPCR Assays in Living Cells, you can:

  • Detect kinetic Gs, Gi, and Gq mediated responses in living cells
  • Combine multiple assays in the same cell population
  • Express sensors and run assays in disease relevant cell types
  • Detect fluorescence on imaging systems or automated plate readers (Z’>0.8)
  • Quantify agonist bias
  • De-orphanize receptors

Detecting Gs

Detect Gs mediated cAMP fluctuations with the cADDis cAMP assay.

→ BMG CLARIOstar® Application Note for Gs

Detecting Gi

Our cADDis cAMP sensor can be also used to detect Gi mediated responses.

→ Request Gi Assay Paper

Detecting Gq


Detect Gq mediated responses using R-GECO Ca2+, DAG, and PIP2 assays.

→ BMG CLARIOstar® Application Note for Gq

Continuous Multiplex Measurements

Red fluorescent DAG sensor multiplexed with cADDis, a green fluorescent cAMP sensor, indicates Gs & Gq signaling via a calcitonin receptor.


Combine our red and green sensors in the same cells to measure multiple analytes simultaneously. Simply add both sensors to the transduction mix. Measure two signals, examine ligand bias, deorphanize GPCRs, and look for off-target GPCR activation.

Assays in Primary Cultures or iPSCs

Detect GPCR mediated responses in cells relevant to your disease, drug target, or biology of interest. Our BacMam-packaged sensors have been used in neurons, cardiomyoctes, islets, and many more primary and iPSC derived cells! Alternate promoters or viral vectors are available by request. The BacMam Transducible Cells page lists some publications showing disease-relevant cells transduced with BacMam. Pictured, at right, are the cADDis cAMP Assay in primary striatal neurons and the Red GECO calcium assay in nCardia’s Cor.4u cardiomyocytes.

Simple Protocol

We strive to create simple protocols with minimal liquid handling. Cell lysis, IBMX, enzymes, and co-factors are not necessary for these assays. Add our sensors to your cells, incubate, add drug, and measure fluorescent changes.

Biased Agonism

Here at Montana Molecular we have developed a prototype sensor for β-arrestin which can be combined with our other assays for GPCR signaling! Is the ability to examine β-arrestin and G-limb signaling in the same living cells of interest to you? Click here to request more information on the prototype or to be added to our beta-testing list.

Quantifying bias is easier than you think.  Check out this video from Pharmechanics to learn how. 

Sound intriguing? Get more details on each of our specific GPCR Assays

cADDis cAMP Assay

DAG Assay

PIP2 Assay

R-GECO Ca2+ Assay

Recent Publications