ChemiScreen™ stable cell lines and Ready-to-Assay™ frozen cells are based on our proprietary Chem-1 and related host cell backgrounds, which contain endogenous expression of Gα15, a promiscuous G protein, to help funnel signaling to a common calcium readout, regardless of G protein coupling status. Additional second messenger signaling, e.g. cAMP and ERK phosphorylation, has been found for many targets, which can be used to perform orthogonal assay confirmation.
ChemiBrite™ stable cell lines and Ready-to-Assay™ frozen cells are engineered to flash with brilliance upon GPCR activation and developed to provide the greatest readout flexibility, including luminescent and fluorescent calcium flux as well as cAMP. These cells express a proprietary mutant version of clytin, a calcium activated photoprotein.
Calcium No WashPLUS Assay Principle
Calcium No WashPLUS
Assay Principle. The esterified (inactive) calcium dye (probe) penetrates the cell membrane and becomes active once inside the cell. The active form of the dye becomes fluorescent after binding to intracellular calcium. Additive A is added to prevent the dye from being released out from the cell. Ligand binding stimulates GPCR activation, resulting in release of intracellular calcium stores from the ER, which leads to an increase in fluorescence in the presence of the activated calcium dye.
Ready-to-Assay™ Frozen Cells
- Calcium No WashPLUS Assay is a rapid, fluorescent dye-based assay qualified for use with all Gq-coupled cell lines
- Coelenterazine H -- All aequorin-based luminescence assays require addition of a coelenterazine substrate. DiscoverX offers an optimized form called Coelenterazine H, a derivative of native coelenterazine that is significantly more sensitive to calcium and provides enhanced performance in aequorin-based luminescent HTS calcium assays.
LeadHunter® GPCR Profiling and Eurofins Discovery Services for GPCRs
Custom Assay Development
Calcium Gq-Coupled Cell Lines
- Native cell lines with unlimited culture and overexpressed naturally Gq-coupled, wild-type GPCRs
- Optimized for use with Calcium No WashPLUS assay for detection of calcium mobilization in response to an agonist stimulation
Calcium No WashPLUS Assay
- Single step, high throughput screening friendly, no wash protocol assay to use with Gq-coupled cell lines
- Detect calcium mobilization in adherent or suspension cells, GPCRs, and calcium ion channels
- Large assay windows, wide dynamic range, and improved signal and performance over FLUO-3
- Multiplex with β-arrestin recruitment assays using the same cell line and the same well for multiple readouts
ChemiScreen™ Cell Lines
- High functional expression of receptors with the ability to assay both agonist and antagonist in a single well
- Stable cell lines for continuous culture with increased reliability and reproducibility assay results
ChemiBrite™ Cell Lines
- Exceptional high signal-to-background ratio with no assay interference with autofluorescent compounds
- Tool box capabilities allows generation of your own stable cell lines
ChemiScreen™ and ChemiBrite™ Frozen Cells
- Ready-to-Assay™ GPCR frozen cells come with plating media and enough cells to run either 96- or 384-well plate assays in full or half plate formats
- Qualified for cAMP and calcium second messenger assays with results within 24 hours to accelerate your data generation
Uncover Unique Pharmacologies, Rank-Order Leads, and Analyze Calcium Flux
Potency and rank order of five Histamine H1 receptor antagonists as assessed by calcium signaling using the Calcium No WashPLUS
kit. Rank order is consistent with affinity data reported for these antagonists in the IUPHAR database. Data kindly provided by Dr. Thierry Calmels at BioProjet Biotech, France.
The small molecule MDL29,951 induces a concentration-dependent agonistic response in calcium signaling after binding to the orphan GPCR, GPR17.
Calcium and ß-Arrestin Detection in the Same Well
DiscoverX offers Gq
-coupled β-arrestin targets as clonal cell lines or ready-to-use kits, to monitor intracellular calcium flux in real time, followed by the recruitment of β-arrestin in the same cell line or in a single well. This HTS-compatible duplexed assay increases your screening capabilities, removes challenges of running multiple assays, reduces data complexity, and provides significant cost savings and time efficiencies.
-coupled PathHunter β-arrestin cell line expressing the Bradykinin B1 Receptor (BDKRB1) was first monitored for calcium mobilization using the Calcium No WashPLUS
Kit as a fluorescent readout. β-Arrestin recruitment was then analyzed in the same well using PathHunter Detection Reagents. This duplexed assay provides a simple and efficient approach for measuring different signaling pathways for the same GPCR and defining potency ranking of GPCR modulators.