Diazo reaction

Diazoreaction is a reaction between group A hemolytic streptococci and non-hemolytic streptococci, which occurs under certain conditions (in the presence of tuberculin and sulfur solution) with the formation of indoxyl purple crystals (cyanoglycine). Used to differentiate hemolytic and non-hemolytic streptococci. Recorded by Enders von Eickstedt in 1892. R. Ehrlich was the first to describe the clinical signs of diazoreaction. The appearance of cyan paint crystals is interpreted as a chemical analogue of the natural lysis of hemolytic streptococcus cells caused by the toxin and endotoxin of the pathogen.

Diazoreaction (Syn. Erlich Diazo Reaction) is a method used in medicine to diagnose various diseases. This method is based on the use of diazo, which is a dye formed by the reaction between a diazo dye and an alkali.

Diazo apparatus according to Erlich To carry out diagnostics, it is necessary to place a sample of the patient's blood or tissue in a test tube containing an alkali solution and a small volume of diazone. The test tube is then shaken and capped. Next, the test tube is placed in a water bath at a temperature of 60 to 70 degrees Celsius for 2-3 hours. As a result of the chemical reaction, the dye is distributed throughout the entire volume of the sample.

Interpretation of the result After the reaction is completed, the sample can be assessed under a microscope for the presence of certain infectious diseases. To do this, microscopic studies are carried out to determine the type and number of microorganisms present in the sample. Other methods can also be used, such as enzyme-linked immunosorbent assay (ELISA), which helps determine the presence of antibodies to certain infectious diseases.

Practical application of this method Diazoreaction is widely used in medical practice for the diagnosis of tuberculosis, diphtheria, whooping cough, influenza, cholera, typhoid fever and other infectious diseases. It is also used to detect hidden infection in immunocompromised patients, as well as to monitor the effectiveness of therapy.

Advantages of the method One of the main advantages of the diazoreaction is its simplicity and low cost. It can be used in the field and does not require complex equipment, making it accessible to a wide range of people. In addition, the diazoreaction can be carried out without the use of an incubator, which allows you to quickly obtain results.

Disadvantages of the method A disadvantage of the diazoreaction can be considered its limited accuracy, especially with small quantities of the infectious agent. Also, this method may have low sensitivity or specificity, especially in cases of severe intoxication or long-term storage of samples. In some cases, the results may be distorted due to incorrect procedures or insufficient qualifications of personnel.