FluxOR™ II Green Potassium Ion Channel Assay

The FluxOR™ II Green Potassium Ion Channel Assay is the next-generation solution for high throughput screening (HTS) of potassium ion channel and transporter activities. The FluxOR II Green assay takes advantage of the permeability of potassium channels to thallium ions. It utilizes an improved thallium-sensitive fluorogenic indicator dye that results in a larger signal window and a significant improvement in the sensitivity of the assay. Also, the assay has been configured to be performed in either a Wash or No Wash format.

Features include:
• Improved assay sensitivity and larger signal window facilitate analysis of a wider range of potassium channels, including low-expressed or weakly conducting channels
• 100% increase in dynamic range compared to previous generation; >40% increase in dynamic range compared to competition
• Homogenous, no-wash protocol reduces well-to-well variation and improves assay reproducibility
• Optimized for high throughput screening applications
• Formatted for low- to high-throughput users

Similar to the previous generation assay, the FluxOR II Green Potassium Ion Channel Assay makes use of the permeability of potassium channels to thallium. When potassium channels are opened by a stimulus, extracellular thallium flows down its concentration gradient into the cells, and channel or transporter activity is detected with a proprietary indicator dye pre-loaded into the cells that increases in cytosolic fluorescence in the presence of thallium. In this way, the fluorescence observed using the FluxOR II assay is an indicator of any ion channel activity or transport process that allows thallium into cells. This fluorogenic signal quantitatively reflects the activity of ion channels and transporters that are permeant to thallium, including hERG, Kir2.1, and other pharmacologically important potassium channels. For the FluxOR II assay, an improved indicator dye was developed, resulting in higher signal windows and improved assay sensitivity.

In addition to an improved fluorescent indicator dye, the FluxOR II Green Potassium Ion Channel Assay provides a concentrated thallium solution and all necessary buffers, allowing maximum target flexibility and ease of operation in a homogenous format that has been demonstrated with cells stably expressing hERG. The assay can be configured for Wash and No Wash formats.