Assay Ready Kit Format Selection Guide

Ready-to-use eXpress™ and eXplorer™ Kits

DiscoverX offers a comprehensive menu of ready-to-use, functional cell-based assays for GPCRs, Kinases, checkpoint receptors, cytokines, epigenetic proteins, NHRs and novel signaling pathways. These kits contain validated cells, detection reagents, cell plating reagents, and plates and do not require expensive instrumentation to run. Eliminate lengthy, expensive and time consuming cell culture.

Simply thaw, plate, and run the assay!

Ready-to-use complete kits for:

  • Target Characterization - Identify targets and validate distinguishing target-specific variations like species, orthologs, isotype, and more during early drug discovery programs
  • Functional & Binding Analysis - Perform quick, high-throughput cell-based assay binding and MOA assessment of your small molecule compounds or biologics
  • Screening & Hit Identification - Identify hits; run primary, secondary and orthogonal screens; and rank-order hits
  • Lead Optimization - Define best leads; optimize lead potencies, efficacy, and specificity; and perform SAR an dligand bias studies

Select one of the tabs below to learn more about these different assay ready formats.

  PathHunter® and cAMP Hunter™ eXpress kits provide a fast and simple method for detection of receptor activation, receptor internalization and other novel cell signaling events, while InCELL Hunter™ and InCELL Pulse™ eXpress kits provide a quick and easy method for determination of compound target engagement (binding) to intracellular targets. All assay-ready eXpress kits are formatted for 96-well plate analysis and are available in multiples sizes.

View List of Assay Ready eXpress Kits »


Features & Advantages

  • Choose from over 400 assays - GPCRs, Kinases, NHRs and signaling pathways
  • Functionally validated frozen cells and reagents
  • Single assay format - detect agonists, antagonists, allosteric modulators
  • Optimized step-by-step protocol
  • Chemiluminescent detection for fast and reliable results
  • Utility for both small molecule and biologics screening
  • Compatible with any standard bench top luminometer
How it Works

Robust and Reliable Assay-Ready Format


Measurement of β-Arrestin recruitment by the Somatostatin 2 (SSTR2) receptor in response to increasing concentrations of Somatostatin-28 (SST-28) using frozen, assay ready eXpress cells and live PathHunter cell lines. PathHunter eXpress cells have EC50 values equivalent to dividing cells.

Highly Reproducible

Individual vials of PathHunter eXpress  GIPR cells were thawed and plated into 96-well dishes on 3 separate days and assay performance was compared. Similar signal to background (S:B) and EC50 values were obtained demonstrating  that the assay ready eXpress format results in robust, reliable and reproducible results  every time.

Adaptable to 96- and 384-well Formats

U2OS PathHunter® eXpress cells expressing the Bradykinin BDKRB1 receptor were plated at 10,000 cells/well in a 96-well plate (left panel) or 2,000 cell/well in a 384-well plate (right panel) and stimulated with a control agonist Lys-des-Arg9 Bradykinin for 90 minutes. Signal was detected using PathHunter® Detection Reagents according to the protocol. Similar pharmacology and signal-to-background was obtained in both formats [click to enlarge].
The PathHunter® GPCR Explorer Kit is a simple and easy-to-use method for building on-demand functional GPCR assays in just 3 simple steps – Clone. Transfect. Read. Whether you have a panel of mutant GPCR cDNAs or a favorite GPCR heterodimer you’d like to functionally test, the simple, optimized transfection protocol combined with PathHunter® EFC-based chemiluminescent detection makes it the ideal platform for exploring novel GPCR receptor biology.

View available GPCR eXplorer kit »

Features & Advantages

  • Based on G-protein independent β-Arrestin read-out
  • Contains highly transfectable, ready-to-assay CHO-K1 cells
  • Choice of vectors optimized for maximal expression in mammalian cells
  • Ideal for GPCR heterodimerization, siRNA knockdown, or mutant receptor studies
  • Chemiluminescent detection used with any standard luminometer
How it Works  

Assay Performance


Create Customized GPCR Biosensor Lines

  Creation of GPCR Biosensor Cell LinesTRKA, TRKB and TRKC inhibition data using Staurosporine           
CHO-K1 GPCR eXplorer cells were plated at 10,000 cells per well and incubated overnight at 37°C. The following day, cells were transfected with 2 µg of pEGFP vector and 48 hr post-transfection, greater than 60% of the GPCR Explorer cells were transfected ([Left panel) [click to enlarge]. In a separate experiment, eXplorer cells were transiently transfected with 2 µg of the pCMV-SSTR2-PK vector (+ SSTR2 DNA) or an empty vector (- SSTR2 DNA). Twenty-four hours later, cells were treated with increasing concentrations of Somatostatin 28, a control agonist. Activation of the SSTR2 receptor stimulates binding of Arrestin resulting in an increase in β-gal enzyme activity that can be measured using chemiluminescent PathHunter Detection Reagents  (Right panel) [click to enlarge].