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Live Cell β-Arrestin Assays

Genetically-encoded fluorescent assay kits detect real-time changes in beta-arrestin activity.
  • Detect agonist bias in living cells

  • Measure kinetic cellular responses

  • Monitor Arrestin and G-limb signaling using the same modality

  • Detect responses simultaneously or in parallel

Kits are available to detect arrestin recruitment at specific GPCRs. Kits include the Arrestin sensor, GPCR and relevant GRK in BacMam, positive control agonist, and sodium butyrate.

Data in figures above (except for Mu Opioid) have been inverted, so the y-axis direction equals the response direction (i.e. an increase in arrestin recruitment). The arrestin sensor decreases in fluorescence intensity when arrestin recruitment increase.

A common assay modality enables reliable measurements of Arrestin and G-protein mediated signaling.

Arrestin and Ca2+ activity at the AT1R measured in parallel plates.  Assay kits: #D1010G and #U0600G.

Angiotensin Receptor AT1R

Arrestin and diacylglycerol (DAG) activity at the AT1R measured simultaneously in the same plate on a BioTek Synergy MX plate reader. Assay kits: #D1010G and #U0300R.

Simple protocol:

Quantify agonist bias with intuitive Phamechanic Tools:

  • Easily capture signaling kinetics
  • Make direct comparisons of arrestin and G-limb activity
  • Monitor the time course of GPCR activity in a single assay

Arrestin Assay FAQs

Can I use a plate reader with the β-arrestin biosensor assay?

We’ve confirmed that the AT1R, β2AR, MOP, GLP-1R and V2R receptors produce robust Z’ values on standard fluorescence plate readers in HEK293T, CHO and U2OS cells. Other cell types and receptors may require imaging to capture signals from individual cells.

Can I detect a response in primary cultures or iPSCs?

We haven’t tried iPSCs or primary cultures for the arrestin biosensors yet, but if you are interested, we can help.

What if I have a cell line already expressing my receptor of interest?

The response will depend on the level of receptor expression in your cell line. If the level is too low in your cell line, we recommend using a BacMam vector to optimize receptor expression. We offer a number of GPCRs in high titer BacMam stock.

Can I detect the activity of endogenously expressed receptors with this assay?

Success will depend on the level of endogenous receptor expression.

Can I express the receptor using a plasmid?

You can, but this will increase variability and reduce Z’. For optimal results, we recommend adding the receptor packaged in BacMam so that you can control the level of receptor expression and reduce cell-to-cell variability.

Can I multiplex the green arrestin biosensor with a red sensor for Ca2+, DAG or cAMP?

Yes you can. We recommend confirming the positive controls in separate experiments before multiplexing the assay.

How do I analyze kinetic data?

The best way to analyze kinetic data from GPCR signaling is with the Pharmechanics GraphPad Prism module.

What β-arrestin biosensor kits are available?

Receptor-specific kits for AT1R, V2R, GLP-1R, MOP, β2AR, and D1-Dopamine are shipping now. Don’t see what you need?

Please let us know [email protected].

What if my receptor of interest is not available?

New receptor-specific kits are coming on line on a regular basis. Please let us know if you do not see the assay you need on our list. We offer custom assay services including:

  • Packaging your receptor in BacMam so you can optimize the arrestin assay.
    The BacMam delivery system allows you to easily control receptor expression and produces low cell-to-cell variability. You receive ~175 mL of high titer BacMam vector, a panel of GRKs, a specific protocol for assay optimization and a 10 mL arrestin biosensor kit.


  • Custom Assay Optimization
    Each receptor is unique when it comes to arrestin biology. To capture the optimal kinetic response it’s important to optimize assay conditions for your receptor. We package your receptor in BacMam, and optimize conditions for your receptor. You receive a detailed report including sample data, a specific protocol, and ~175 mL of your receptor in high titer BacMam stock.

Beta Arrestin Assay Posters

Watching Biased Agonism at GPCRs in Real Time

Coloring Beta-arrestin signaling green, and G-protein signaling red, a new live cell assay for quantitatively measuring agonist bias at seven transmembrane domain receptors.

Measuring biased agonism with a kinetic analysis platform for real time data from fluorescent biosensors

cADDis cAMP Assay

DAG Assay

PIP2 Assay

GECO Ca2+ Assay