Luminol monosodium salt, also known as 3-aminophthalhydrazide monosodium salt in Chinese, has a CAS number of 20666-12-0 and a molecular formula of C8H8N3NaO2. It has good water solubility and is a commonly used chemiluminescent reagent. Due to differences in production processes among different manufacturers, the appearance of Lumino monosodium salts is commonly seen as light green, light yellow, or off white powder on the market. Among them, off white Lumino monosodium salt powder is more widely recognized by the public and needs to be prepared as a solution when used. Lumino monosodium salt is a derivative of Lumino luminescent ammonia, so there are many commonalities in use: firstly, Lumino and Lumino monosodium salt require catalysis to emit light, and both can be used to detect bloodstains. In contrast, luminol monosodium salt is more suitable for blood stain detection, because luminol is an acidic substance that is insoluble in water and soluble in alkaline solutions, while luminol monosodium salt is soluble in water and closer to the pH value of human blood, both approaching 7. The use of luminol monosodium salt is not only to detect blood stains and crime scenes, but also to detect peroxidase. It is also a metal ion mediated oxidation sensitive probe and a commonly used reagent in chemiluminescence analysis of metal cations and glucocorticoids. It can also image myeloperoxidase activity in the body. In summary, the use of luminol monosodium salt is very flexible and extensive.