1. 🔬 Biochemistry and Molecular Biology Research
• Alkaline Phosphatase (ALP) Detection: NBT is the most classic and widely used method. When used in combination with another substrate, BCIP, under the catalysis of alkaline phosphatase, it produces a water-insoluble dark blue to bluish-purple precipitate. This reaction is used in:

• Western Blotting: Detecting proteins separated by electrophoresis and transferred to a membrane.

• Immunohistochemistry (IHC) and Immunocytochemistry (ICC): Localizing specific antigens in tissue sections or cell samples.

• Dehydrogenase and Oxidase Detection: NBT can serve as a substrate for various dehydrogenases (such as glucose-6-phosphate dehydrogenase). In the presence of these enzymes, NBT is reduced to a dark formazan product, indicating enzyme activity.

• Superoxide Anion Detection: NBT is a known superoxide anion scavenger and can be used in biochemical experiments to detect or verify the production of superoxide anions.

• Nitric Oxide Synthase (NOS) Inhibition: NBT has been reported to competitively inhibit nitric oxide synthase activity, with an IC50 of 3-4 μM, and can be used in related research.

2. 🏥 Clinical Diagnosis and Testing
• Cell Immunoassay (NBT Reduction Test): This is a clinical test used to assess the body’s immune function, particularly the bactericidal capacity of neutrophils. Elevated positive results (usually >10%) may suggest systemic bacterial or fungal infection, while abnormally low values ​​are associated with immunodeficiency such as chronic granulomatous disease.

• Other Disease Auxiliary Diagnosis: According to chemical database information, NBT-related techniques have also been explored or applied in the diagnostic research of various diseases, including Alzheimer’s disease, bacterial vaginosis, childhood behavioral disorders, and congenital megacolon.

3. 🧪 Other Special Applications
• Biochemical Indicator Measurement: Some literature mentions that the NBT reduction method can be used to determine the concentration of glycated low-density lipoprotein and very low-density lipoprotein in serum.

• Coagulation Factor Precipitation: NBT can be used as a precipitating agent for coagulation factor I (fibrinogen).