Esterase is mainly divided into non-specific esterase (non-specific esterase), esterase (lipase), cholinesterase (choli-esterase), each kind of esterase can often hydrolyze many different substrates, a variety of different esterases can hydrolyze the same substrate, so this series of esterases is known as non-specific esterases, non-specific esterases optimal pH The optimal pH of non-specific esterases is 5.0-8.0, and they are localized in lysosomes and endoplasmic reticulum. They have high enzyme activities in liver, kidney, pancreas and small intestine, and the monocyte-phagocyte system of monocytes, macrophages, and dendritic cells also contain abundant non-specific esterases.

α-Naphthol acetate esterase staining solution (α-NAE method), also known as non-specific esterase staining solution, the principle is that the non-specific esterase in the cell will be hydrolyzed by α-acetate naphthol to produce α-naphthol, α-naphthol and then coupled with diazonium salts, generating an insoluble colored precipitate, which is localized in the cytoplasm, the staining solution is not specific for esterase staining, so it is also known as non-specific esterase staining solution, which can be used for blood, bone marrow, or cells. It can be used for non-specific esterase staining of blood, bone marrow or cell smears, frozen sections, and can also be used for sodium fluoride inhibition test.