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Thallium Flux Assay for Measuring the Activity of Monovalent Cation Channels and Transporters

Part of the Methods in Molecular Biology book series (MIMB,volume 1684)


Monovalent cation channels are critically important for physiological processes ranging from the control of neuronal excitability to the maintenance of solute balance. Mutations in these channels are associated with a multiplicity of diseases and monovalent cation channel-modulating drugs are used as therapeutics. Techniques that allow the measurement of the activity of these ion channels are useful for exploring their many biological roles as well as enabling the discovery and characterization of ion channel modulators for the purposes of drug discovery. Although there are numerous techniques for measuring the activity of monovalent cation channels, the thallium flux assay technique is a widely used fluorescence-based approach. Described herein is a method for using the thallium-flux technique for detecting and quantifying the activity of small-molecule potassium channel modulators in 384-well plates.

Key words

  • Ion channel
  • Potassium channel
  • Sodium channel
  • Drug discovery
  • High-throughput screening
  • Fluorescent dye
  • Thallium

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This work was supported by the Vanderbilt Department of Pharmacology and the Vanderbilt Institute of Chemical Biology.

Conflict of Interest: CDW receives royalties from the sales of the Panoptic kinetic imaging plate reader, ThaLux Green, and the FLIPR Potassium Assay Kit. CDW is an owner of WaveFront Biosciences.

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Correspondence to C. David Weaver .

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Weaver, C.D. (2018). Thallium Flux Assay for Measuring the Activity of Monovalent Cation Channels and Transporters. In: Shyng, SL., Valiyaveetil, F., Whorton, M. (eds) Potassium Channels. Methods in Molecular Biology, vol 1684. Humana Press, New York, NY.

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