ION Biosciences' Brilliant Sodium 2 Assay Flex kit is a second-generation, fluorescence-based solution designed for high-throughput screening of NaV1.X modulators. At its core is ION Natrium Green 2 AM (ING-2 AM), a membrane-permeable, sodium-sensitive, fluorescent dye that enables real-time, direct measurement of intracellular sodium channel activity. Compared to the original version, Brilliant Sodium 2 delivers larger signal amplitudes and an expanded screening window, making it well-suited for determining EC50 or IC50 values of NaV1.X activators and inhibitors. Activation of NaV1.X channels by membrane depolarization or direct stimulation causes a rapid influx of sodium ions, leading to a robust fluorescence increase. This change provides a sensitive and quantitative readout of NaV1.X channel activity and pharmacological modulation. 10 plate kit.