Flux assays in high throughput screening of ion channels in drug discovery

Assay Drug Dev Technol. 2003 Oct;1(5):709-17. doi: 10.1089/154065803770381066.


Ion channels have been identified as therapeutic targets in various disorders, such as cardiovascular disease, neurological disease, and cystic fibrosis. Flux assays to detect functional ionic flux through ion channels are becoming increasingly popular as tools for screening compounds. In an optimized flux assay, modulation of ion channel activity may produce readily detectable changes in radiolabeled or nonradiolabeled ionic flux. Technologies based on flux assays are currently available in a fully automated high throughput format for efficient screening. This application offers sensitive, precise, and reproducible measurements giving accurate drug rank orders matching those of patch clamp data. Conveniently, the flux assay is amenable to adaptation for different ion channels, such as potassium, sodium, calcium, and chloride channels, by using suitable tracer ions. The nonradiolabeled rubidium-based flux assay coupled with the ion channel reader (ICR) technology has become very successful in ion channel activity analysis and is emerging as a popular technique in modern drug discovery.

Publication types

  • Comparative Study
  • Evaluation Study
  • Review

MeSH terms

  • Animals
  • Drug Evaluation, Preclinical / instrumentation
  • Drug Evaluation, Preclinical / methods*
  • Humans
  • Ion Channels / analysis
  • Ion Channels / drug effects*
  • Ion Channels / physiology*
  • Ion Transport / drug effects*
  • Ion Transport / physiology*
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Patch-Clamp Techniques / instrumentation
  • Patch-Clamp Techniques / methods*
  • Radioligand Assay / instrumentation
  • Radioligand Assay / methods*
  • Spectrometry, Fluorescence / instrumentation
  • Spectrometry, Fluorescence / methods*
  • Technology Assessment, Biomedical


  • Ion Channels