Nitro blue tetrazolium is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

composed of two

tetrazole Tetrazoles are a class of synthetic organic heterocyclic compound, consisting of a 5-member ring of four nitrogen atoms and one carbon atom. The name tetrazole also refers to the parent compound with formula CH2N4, of which three isomers can be f ...

moieties. It is used in

immunology Immunology is a branch of medicineImmunology for Medical Students, Roderick Nairn, Matthew Helbert, Mosby, 2007 and biology that covers the medical study of immune systems in humans, animals, plants and sapient species. In such we can see there ...

for sensitive detection of

alkaline phosphatase The enzyme alkaline phosphatase (EC 3.1.3.1, alkaline phosphomonoesterase; phosphomonoesterase; glycerophosphatase; alkaline phosphohydrolase; alkaline phenyl phosphatase; orthophosphoric-monoester phosphohydrolase (alkaline optimum), systematic ...

(with BCIP). NBT serves as the

oxidant An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...

and BCIP is the AP- substrate (and gives also dark blue dye).

Clinical significance

immunohistochemistry Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to an ...

the alkaline phosphatase is often used as a marker, conjugated to an

antibody An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

. The colored product can either be of the NBT/BCIP reaction reveals where the antibody is bound, or can be used in

immunofluorescence Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on microbiological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specif ...

. The NBT/BCIP reaction is also used for colorimetric/

spectrophotometric Spectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. Spectrophotometry uses photometers, known as spec ...

activity assays of

oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ut ...

s. One application is in activity stains in

gel electrophoresis Gel electrophoresis is a method for separation and analysis of biomacromolecules ( DNA, RNA, proteins, etc.) and their fragments, based on their size and charge. It is used in clinical chemistry to separate proteins by charge or size (IEF ...

, such as with the mitochondrial

electron transport chain An electron transport chain (ETC) is a series of protein complexes and other molecules that transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples th ...

complexes. Nitro blue tetrazolium is used in a diagnostic test, particularly for chronic granulomatous disease and other diseases of phagocyte function. When there is an NADPH oxidase defect, the phagocyte is unable to make reactive oxygen species or radicals required for bacterial killing. As a result, bacteria may thrive within the phagocyte. The higher the blue score, the better the cell is at producing reactive oxygen species.

References

{{DEFAULTSORT:Nitro Blue Tetrazolium Chloride Nitrobenzenes Tetrazoles Phenol ethers Immunologic tests