LDH 细胞毒性检测

Lactate dehydrogenase (LDH) is a soluble cytosolic enzyme present in most eukaryotic cells. LDH releases into culture medium upon cell death due to damage of plasma membrane. The increase of the LDH activity in culture supernatant is proportional to the number of lysed cells. LDH Cytotoxicity Assay kit provides a colorimetric method to measure LDH activity using a reaction cocktail containing lactate, NAD+, Diaphorase and INT. LDH catalyzes the reduction of NAD+ to NADH in the presence of L-lactate, while the formation of NADH can be measured in a coupled reaction in which the tetrazolium salt INT is reduced to a red formazan product. The amount of the highly colored and soluble formazan can be measured at 490 nm spectrophotometrically.

乳酸脱氢酶（LDH）是一种存在于大多数真核细胞胞质中的可溶性酶。当细胞因质膜受损而发生死亡时，LDH 会释放至培养基中。培养上清液中 LDH 活性的升高与裂解细胞的数量成正比，因此可作为评估细胞毒性的重要指标。

LDH 细胞毒性检测试剂盒采用比色法检测 LDH 活性，反应体系包含乳酸、NAD⁺、心肌黄酶（Diaphorase）和碘硝基四唑氯化物（INT）。在 L-乳酸存在的条件下，LDH 催化 NAD⁺ 还原生成 NADH；随后，在偶联反应中，NADH 促使四唑盐 INT 被还原生成红色甲臜（Formazan）产物。生成的甲臜具有较高的水溶性和显色强度，可通过分光光度法在 490 nm 波长下进行定量检测。