GPCRs and Ion Channels
We offer a variety of assay and instrument solutions to support studies of GPCR and ion channel function including assay kits, cellular screening and imaging systems, and microplate readers.
GPCRs (G protein-coupled receptors) are the largest protein family, with between 600 and 1000 members, and have been linked to many normal biological as well as pathological conditions. They are also known as seven transmembrane (7-TM) receptors, and about 45% of modern medicinal drugs affect this target class. The function of GPCRs is highly diverse, recognizing a wide range of ligands, including photons, small molecules, and proteins. Ion channels are pores in the cellular membrane that allow ions to pass in and out of the cell. There are over 400 genes for ion channels in the human genome. Many of them have been targeted by drugs that are now blockbusters. Direct measurement of ion channel activity is measured using traditional electrophysiology equipment for patch-clamping. However, the throughput is very low. Ion channel activity can also be measured indirectly with much higher throughput by using fluophores sensitive to changes in membrane potential, calcium flux, and potassium flux.
FLIPR Calcium Assay Kits from Molecular Devices employ sensitive calcium indicators and proprietary masking dyes to enable researchers to conduct highly sensitive fluorescent screens…
Techniques of GPCRs and Ion Channels
The evaluation of calcium flux is a long accepted, tried and true measure of cellular activity. Calcium flux can be used as a measurement for a host of cellular processes including neurotransmitter release, GPCR activity, voltage or ligand gated ion channels, and cardiomyocyte beat patterns, among many others. The FLIPR Tetra System is the drug discovery tool for evaluation of calcium flux in high and ultra-high throughput due to its ease of use, sensitivity and user configurability.
Monitoring Gq-Coupled Protein Receptor Activity
Gq protein-coupled receptor activation is commonly monitored in live cells in real time using calcium-sensitive dyes on a fluorescence plate reader. Automated liquid handling within the plate reader is generally required to deliver agonist compounds to the cells in the microplate while the detection system takes real-time readings of compound-induced changes in fluorescence intensity values. Analysis of the resulting kinetic readings yields information about the compound response profiles, including EC50 and IC50 values for agonists and antagonists.
Live Cell Kinetic Assays
The ImageXpress Confocal and Micro 4 High-Content Imaging Systems offer optional fluidics and environmental control modules, enabling single-channel pipetting for compound addition and media exchange during rapid kinetics or extended time-lapse experiments. The Transfluor Cell-Based GPCR Assay Kit is a valuable tool used during high content screening (HCS) to track G-protein coupled receptor (GPCR) activation by quantifying GPCR desensitization and recycling using GFP-labeled ß-arrestin with automated image analysis.
Early prediction of drug-induced functional cardiotoxicity requires robust in vitro systems suitable for high-throughput screening. Readily-available iPSC-derived human cardiomyocytes may be used in conjunction with calcium-sensitive dyes, and beat rates are monitored as changes in intracellular calcium. These calcium peaks can be analyzed with our ScreenWorks PeakPro software which provides the investigator a suite of powerful tools for quantification of cardiomyocyte activity.
Functional evaluation of potassium ion channels in a cell is of critical importance in the drug discovery process, particularly when it involves cardiac safety. The FLIPR® Potassium Assay Kit exploits the permeability of thallium ions (Tl+) through both voltage- and ligand-gated potassium (K+) channels. In this assay, a novel, highly-sensitive Tl+ indicator dye produces a bright fluorescent signal proportional to the number of potassium channels in the open state providing a functional indication of the potassium channel activities
Membrane Potential Assays
Voltage-gated ion channels are present in the excitable cell membranes of heart, skeletal muscle, brain and nerve cells. Blocking or modulating such channels can have a therapeutic effect, or may interfere with normal cell function. As a result, compounds that affect voltage-gated ion channels are important targets in drug discovery.
Resources of GPCRs and Ion Channels
FLIPR Calcium Assay Kits from Molecular Devices employ sensitive calcium indicators and proprietary masking dyes to enable researchers to conduct highly sensitive fluorescent screens of G…
Cell Based Assays on the FLIPR® Tetra System : Comparison of a Novel FLIPR® Calcium Assay to Other Fluorescence Based Calcium Flux Assays
Read this poster to see how FLIPR Calcium 6 kit is optimized and how it compares to other fluorescent calcium flux assays.
Validation of TRPV1 and ASIC1 Ligand-Gated Ion Channels using Automated Patch Clamp and FLIPR with novel Ca2+ detection dye
In one series of experiments, we constructed and validated cell based assays in which the FLIPR Calcium 6 assay kit containing this novel calcium fluorophore was used to examine the activity…
Fura-2 QBT Ratiometric Calcium Kit, a Novel Homogeneous Assay for Measuring Calcium Flux Assays on the FLIPR Tetra System and the FlexStation 3 Microplate Reader
This PDF introduces Fura-2 QBT ratiometric calcium kit which saves time and buffer costs & offers less well to well variability, and a larger signal window.
Optimizing a Transient Receptor Potential (TRP) Channel Assay on the FLIPRTETRA® Instrument using hTRPV1-HEK293 Cells and the FLIPR® Calcium 5 Assay Kit
This PDF describes optimization of the TRP (transient receptor potential) channel assay on the FLIPR TETRA instrument using hTRPV1-HEK293 cells and the FLIPR calcium 5 assay kit.
Functional Characterisation of Recombinant Muscarinic M3 Receptors in Assay-Ready Frozen Cells using a Novel Calcium Assay Kit on the FLIPRTETRA® Instrument
This poster compares the performance of cryopreserved "frozen" cells vs. cells in culture when used for screening GPRC drug candidates on the FLIPR Tetra instrument.
Cell Based Assays on the FLIPR TETRA® System : Comparison of the FLIPR Calcium 5 Assay Kit to Other Fluorescence Based Calcium Flux Assays
This poster explores FLIPR Calcium 5 Assay Kit containing a superior performance calcium-sensitive indicator that does not require media removal & utilizes same proven quench technology…
The Fura-2 QBT Calcium Kit from Molecular Devices incorporates proven quench based technology with a ratiometric Fura-2 calcium indicator to provide a homogenous assay to minimize cell…
FLIPR® Calcium Assay Kits from Molecular Devices employ sensitive calcium indicators and proprietary masking dyes to enable researchers to conduct highly sensitive fluorescent screens of G-…
In this application protocol we demonstrate the use of the modified luminescent firefly luciferase-based Promega GloSensor™ cAMP Assay on the FLIPR Tetra® High Throughput Cellular Screening…
Eliminate cardiotoxic compounds and identify potential cardiac drug candidates earlier in the drug discovery process with the FLIPR Tetra System, together with ScreenWorks Peak Pro Software…
The ImageXpress® Micro Confocal/ XLS Widefield High-Content Imaging System from Molecular Devices includes optional Fluidics and Environmental Control modules, enabling single-channel…
Calcium Release-Activated Channel (CRAC) Assays on the FLIPR® Tetra System: Evaluation of a Novel Fluorescent Calcium Reagent
Get detailed information about Calcium release-activated calcium channels by exploring this PDF. Learn how CRAC channels are playing an important role in intracellular Ca2+ homeostasis.
Ready to get started?
We are ready to help you solve your tough research challenges. Our proven solutions and highly qualified teams across the globe can help advance your next big discovery.