Amplite® Fluorimetric NAD/NADH Ratio Assay Kit provides a sensitive, reliable, and fluorescence-based method for quantifying NAD, NADH, and their ratio in biological samples. Traditional NAD/NADH assays measure absorbance at 340 nm, which requires UV-transparent plates and suffers from low sensitivity and high interference. In contrast, this kit uses a proprietary enzyme cycling reaction that amplifies the signal for improved sensitivity and allows detection in the red visible range, significantly reducing background interference. The assay is compatible with 96- and 384-well formats and is ideal for high-throughput screening, metabolic profiling, redox state assessment, and mitochondrial function studies. No sample purification is required, and the protocol is streamlined for automation and reproducibility. The use of red fluorescence (Ex/Em = 540/590 nm) ensures robust detection with minimal interference from sample components.