Naphthol-Peroxidase Reaction

The naphthol peroxidase reaction is a method for detecting peroxidases (enzymes that catalyze the oxidation of substrates) in tissues. This method is based on the oxidation of naphthol (an inorganic compound) with hydrogen peroxide in the presence of peroxidase. As a result, naphtholic acid is formed, which is then oxidized to naphthol-3,6-dicarboxylic acid. This leads to the formation of red granules that are visible under a microscope.

Naphthol peroxidase reactions are widely used in histology and cytochemistry for the detection of peroxidases, which may be associated with various diseases such as cancer, diabetes, heart disease and others. In addition, this method is used in the biochemical industry to determine the activity of peroxidases.

One of the advantages of the naphthol peroxidase reaction is its high sensitivity and specificity. It allows the detection of even small amounts of peroxidases without the need for expensive reagents and equipment. In addition, the method can be used to study tissues at various levels, from cells to entire organs.

However, like any other method, the naphthol-peroxidase reaction has its limitations. For example, it may give false-positive results in the presence of other enzymes that can also oxidize naphthol. In addition, some tissues may have low peroxidase activity or be insensitive to this method.

Overall, the naphthol peroxidase reaction is a useful tool for studying peroxidases in tissues and can be used in various fields of medicine and biology.

Naphthol (ortho-tolidine) is a weak semiquinone, easily oxidized by hydrogen peroxide, with which it forms a red complex. In an alkaline environment, NaOH with a Na2S2O8 solution gives a reddish-orange color to the micropreparation. The coloring is due to the oxidation of naphthol, reduced to a quinone-like state by the dye to peroxazone chloride. Azo pigments (eosins), added to the test material as an indicator of diffonia, make the coloring more intense. Since naphthol has the ability to oxidize only in the presence of alkaline oxidation products with a sulfite-bichromate mixture; painting takes away a certain amount of hydrogen peroxide. Sulfites and their aldimethine residues contribute to the resistance of the redox process to alkali. For this reason, peroxide staining with benazyl, azurin and naphthol cannot be detected in some areas in either children or adults.

Naphthol - peroxidase (thiacetazo - naphtha) reaction

The reaction is based on the peroxide oxygenase ability of alkaline proteins, which are converted into red granules and are called **thyroglobulin** or alkaline protein. It is used to detect the enzyme peroxidase in tissue.

It is also used in histochemistry and microbiology. The method provides rapid, direct access to the surface localization of peroxide that has been detected on the cell surface. It has proven particularly useful in studies of the role of peroxides in oxidative stress