Isocitrate dehydrogenase (IDH) is one of the inverters in the tricarboxylic acid cycle and plays an important role in energy metabolism, amino acid and vitamin synthesis. The cofactors of this enzyme include two kinds of NAD+ and NADP+, which are located in different parts of the cell respectively. In eukaryotic cells, NAD-dependent isocitrate dehydrogenase mainly exists in mitochondria. Under the activation of the activator, IDH converts isocitrate into α-ketoglutaric acid. Meanwhile, NAD+ is reduced to NADH, which under the action of hydrogen transmitter, transfer electrons to WST-8 to produce the yellow product. The activity of NAD-IDH can be calculated by measuring the change of absorbance value at 450 nm.
