The NAD/NADH-Glo Assay is a bioluminescent, homogeneous single-reagent-addition assay for detecting total oxidized and reduced nicotinamide adenine dinucleotides (NAD+ and NADH, respectively) and determining their ratio in biological samples or in defined enzyme reactions. An NAD Cycling Enzyme is used to convert NAD+ to NADH. In the presence of NADH, the provided reductase enzyme reduces a proluciferin reductase substrate to form luciferin. Luciferin then is quantified using Ultra-Glo Recombinant Luciferase, and the light signal produced is proportional to the amount of NAD+ and NADH in the sample. Cycling between NAD+ and NADH by the NAD Cycling Enzyme and Reductase increases assay sensitivity and provides selectivity for the nonphosphorylated NAD+ and NADH compared to the phosphorylated forms NADP+ and NADPH. The NAD Cycling Enzyme, Reductase and luciferase reactions are initiated by adding an equal volume of NAD/NADH-Glo Detection Reagent, which contains NAD Cycling Enzyme and Substrate, Reductase, Reductase Substrate and Ultra-Glo Recombinant Luciferase, to an NAD+- or NADH-containing sample. Detergent present in the reagent lyses cells, allowing detection of total cellular NAD+ and NADH in a multiwell format with addition of a single reagent. An accessory protocol is provided to allow separate measurements of NAD+ and NADH, and calculation of the NAD+ to NADH ratio. The simple add-mix-read protocol and scalable assay chemistry make the NAD/NADH-Glo Assay well suited to monitor effects of small molecule compounds on NAD and NADH levels in high-throughput formats.|
High Sensitivity: High sensitivity of the assay enables detection of total NAD+ and NADH directly in the wells. Fewer cells are required, with no sample preparation. Homogeneous, One-Step Protocol: Total NAD+ and NADH is measured directly in wells of a 96- or 384-well cell culture plate with one reagent addition. A simple in-plate protocol is provided for individual NAD+ and NADH measurements. Large Assay Window: The NAD/NADH-Glo(TM); Assay detects 10nM to 400nM NAD+ or NADH. The assay detects 100nM with a signal higher than fivefold over background and an assay window (maximum signal-to-background ratio) of ≥100. Automation Compatible: The assay is compatible with automated and high-throughput protocols. Reactions are scalable and can be performed at low volumes in 96-, 384- and 1536-well plates. Reliability and Reproducibility: The NAD/NADH-Glo(TM); Assay routinely yields Z factors more than0.7. Luminescence-Based NAD+ and NADH Detection: The luminescent format avoids fluorescent interference due to reagents and test compounds sometimes seen in fluorescent assays.