Ion Channel Screening Technologies and Platforms
Charles River scientists have pioneered ion channel research and screening services for 20 years, creating more than 120 functionally validated assays and cell lines. We offer a variety of cutting-edge technologies for ion channel screening, profiling and mechanism of action (MOA) studies, supporting our partners’ quests for the discovery of novel ion channel therapeutics.
High-Throughput Screening Technologies for Ion Channels
Hit identification from large compound libraries using High-throughput screening (HTS) technologies is a critical step in early drug discovery. Hits are defined by efficacy, potency and specificity for the ion channel of interest, and their potential for off-target side effects. Our compound identification services use fluorescence-based, automated patch-clamp and conventional (manual patch) electrophysiology assays. Assays can be conducted against a large collection of over 120 ion channels expressed in mammalian cells.
Eliminate having to repeat studies and long testing cycles by choosing high-throughput electrophysiology for large voltage-gated and ligand-gated ion channel HTS campaigns using the Sophion Qube platform:
- Giga-seal quality data
- 384-well plates
- Profiling can be conducted on the same instrument for a seamless ion channel screening cascade
How many compounds can be screened in a high-throughput ion channel assay?
Charles River have carried out ion channel screens implementing high-throughput electrophysiology on compound libraries of up to 730,000 compounds.
Hit-to-Lead and Lead Optimization for Ion Channel Research
- Gain detailed pharmacological and biophysical follow-up studies using conventional platforms and the Sophion QPatch HT® automated electrophysiology technology.
- Perform fluorescence-based screens of up to 1,000,000 compounds with the FLIPR® platform.
- Capture large-scale transient expression using MaxCyte® STX™, allowing 40 million to 10 billion cells per transfection.
-
Epithelial Short-Circuit Current Assays
Using chamber assays (UCA) measure ionic currents across polarized epithelial cell layers (maintained in culture—either primary cells or clonal cell lines) in drug discovery and toxicology evaluations. Chronic and acute test article modulation of transepithelial current, resistance, and potential are quantitated.
- Determine concentration-response relationships for CFTR modulators or inhibitors
- Screen against the ΔF508-CFTR (associated with cystic fibrosis [CF]) in CF patient-derived bronchial epithelial (CFhBE) primary cultures
- Screen against wild-type CFTR in NhBE cells from normal patients
- Evaluate effects on epithelial sodium channel (ENaC), an important target in hypertension and CF in NhBE
-
Ion Channel Selectivity Profiling Assays
Identification of a compound's target specificity and potential for off-target effects is a critical step in the drug discovery process and often includes assessments against specific target class families, critical safety targets or by therapeutic area.
Charles River offers the largest collection of validated functional assays for ion channel selectivity profiling. Our portfolio includes over 120 ion channel assays, which have been organized into Channel Panels® based on current scientific findings. We can provide functional, manual and automated ion channel screening by therapeutic area for profiling and risk assessment.
Available Channel Panels®:
- Cancer
- Cardiac
- Cardiovascular
- Genitourinary
- Metabolic and Gastrointestinal
- Neurodegeneration/Stroke
- Pain/Inflammation
- Psychiatric Disorder
- Pulmonary/Respiratory
- Seizure/Convulsion
-
Ion Channel Trafficking Assays
Functional ion channel activity can be hindered by prolonged exposure to drugs that inhibit trafficking of the channel protein from cytoplasmic sites to the surface membrane.
HERG-Lite® and CHAN-Lite® are chemiluminescent assays that identify trafficking inhibition in cardiac cell lines following overnight drug exposure.
Benefits:
- Determine specificity of drug-induced trafficking inhibition
- Identify compounds that enhance cell-surface expression
- Rapid results
-
De-risking cardiac ion channel activity to predict cardiac liabilities: CiPA Ion Channel Assays
Current regulations require potential novel drugs to be tested against hERG and a comprehensive QT interval study.
The CiPA initiative extended the required screening to include more ion channels involved in controlling the ventricular action potential: hERG (IKr), NaV1.5 (INa) and CaV1.2 (ICaL) are defined as the CiPA core, whilst KV4.3 (Ito), Kir2.1 (IK1), KVLQT1 (IKs) form a second tier.
Testing against the entire ion channel panel can help identify cardiac liabilities, and provides more reliable predictions of the cardiac safety profile early in the drug development process.
Associated ion channel screening services
- Computational chemistry for knowledge-based compound deck selection from our 1.4 million diverse compound library
- Assay development and transfer services to compliment your current study design.
- Ion channel selectivity profiling
- Hit-to-lead and lead optimization support using fluorescence-based, automated and conventional electrophysiology
- Custom cell line generation – single alpha subunits to more complex multi-subunit combinations, constitutive and inducible expression vectors
- Access to fluorescence-activated cell sorting
Frequently Asked Questions (FAQs) About Ion Channel Assays and Screening
-
How many positive and negative controls should be used per plate to achieve good Z values?
We recommend using 16 wells with DMSO controls and 16 wells as a positive control for full inhibition. These are recommended controls for FLIPR®, IonWorks® and Qube™ systems.
-
What are some differences between fluorescence and radiometric outputs?
With the radiometric technique, a well-validated ligand needs to be used for displacement to be measured as the technique is quite sensitive. Fluorescent techniques are easier to develop, but there is a risk of false positives with compounds that interact with the fluorescent response. It is recommended to include an automated electrophysiology assay after the fluorescence-based screen to quickly identify false positives.
-
Are post-translational modifications always required for ion channels to be functional in your cell lines?
Yes, ion channels need to be appropriately post-translationally modified to be functional so that current flow can be recorded.
-
What are the advantages and disadvantages of automated electrophysiology compared to fluorescent techniques?
Fluorescent techniques are easier to configure and faster than electrophysiology, and typically you can screen a hundred 384-well plates a day. Automated electrophysiology is comparatively slower—a typical assay takes 30–45 minutes to screen one plate, so 10–20 plates can be screened in a day. The advantage of automated electrophysiology is the generation of data to support a deeper understanding of how a compound interacts with a target. Depending on the target, we may recommend first performing a fluorescent screen followed by automated electrophysiology.
-
What's your electrophysiological data analysis tool for screening?
For certain automated electrophysiology platforms, we use the software that is supplied with the instrument (Sophion Qube™ or QPatch). For fluorescent assays, the output is analyzed using GeneData.
-
What are the typical levels of ion channel expression in your cell lines, in copies per cell?
The typical number of copies per cell is 10,000–30,000 copies.