Screen Quest? Colorimetric Chloride Channel Assay Kit. Chloride channels have a variety of important physiological and cellular functions that include regulation of pH, volume homeostasis, organic solute transport, cell migration, cell proliferation and differentiation. Chloride channels represent valuable drug targets. A number of chronic disease states such as cystic fibrosis and Bartter's syndrome are due to defects in chloride channel functions. However, the existing technologies for screening chloride channel modulators are a compromise between throughput, sensitivity and physiological relevance. Screen Quest? Colorimetric Chloride Channel Assay Kit provides a sensitive and robust colorimetric method for studying chloride channels. The assay is based on our proprietary iodide indicator (Iodide Blue?) for measuring iodide concentration, as low as 30 nM of iodide was detected by this assay. Screen Quest? Chloride Channel Assay Kit provides an optimized assay method for monitoring chloride channels. The assay can be performed in a convenient 96-well or 384-well microtiter-plate format and easily adapted to automation.