Nicotinamide adenine dinucleotide phosphate (NADP+) is used in anabolic reactions, such as lipid and nucleic acid synthesis, which require NADPH as a reducing agent. NADPH is the reduced form of NADP+, and NADP+ is the oxidized form of NADPH. In cells, NADPH plays the role of a carrier of reducing power and is primarily involved in maintaining optimal redox metabolism. A simplified assay for the measurement of NAD and NADP is critical to understanding the roles of these pyridine nucleotides in normal and abnormal cells.

NADPH is produced in the oxidative phase of the pentose phosphate pathway in cells, a multifunctional pathway whose primary purpose is to generate reducing power in the form of NADPH. NADPH is a cofactor for enzymes that synthesize energy-rich molecules and provide the reducing equivalents for the oxidation-reduction involved in protecting the cell from the toxicity of reactive oxygen species (ROS) and NADPH oxidase-dependent ROS generation. Both NAD and NADP have been shown to influence hemoglobin affinity for oxygen in erythrocytes. In plant cells, NADPH is used as the reducing power for the biosynthetic reactions in the Calvin cycle of photosynthesis.

Our Fluorescent NADP/NADPH Detection Kit provides a reliable, sensitive fluorometric assay for the quantification of NADP, NADPH and their ratio in biological samples. The kit can be used with mammalian cells and tissues, and bacterial, fungal and plant cells.

The kit utilizes a non-fluorescent detection reagent, which is reduced in the presence of NADPH to produce its fluorescent analog and NADP. NADP is further converted to NADPH via an enzyme-coupled reaction. The enzymes in the reactions specifically react with NADP/NADPH and not with NAD/NADH.