Board - Zhang reaction

Board - Zhang response (reaction of binding complement, RSK) - immunological response, based on the property complex antigen - antibody commit a free complement. RAC proceeds in two phases: 1) adsorption of antibodies to antigens; 2) the expression of the reaction in the presence of hemolytic system (hemolysis). For statement of RAC objects of investigation (antibodies and antigens) are placed in conditions providing their interaction in the presence of complement; then to analyze the immune system add "indicator" - haemolytic system. If the complement was recorded by the immune system, hemolysis is not happening (positive RAC; figure, a); if the immune system is not recorded complement and its components do not match each other, hemolysis is the (negative RAC; figure, b). Ingredients reactions: 1) test serum, inactivated by heating for 30 minutes at temperature of 56 degrees; 2) antigen (suspension of bacteria, extracts of organs and tissues, viruses); 3) complement (fresh serum Guinea pigs); 4) haemolytic system (sensitized red blood cells sheep, incubated with haemolytic serum within 30 minutes at temperature of 37 degrees). For cultivation of ingredients used isotonic solution of sodium chloride. The first stage RAC lasts 60 minutes at temperature 37 degree or 18-20 hour. when temperature is 4-6'c (more sensitive RSK), the second phase - 60 minutes at temperature of 37 degrees.
In diagnostic practice and forensic medicine uses various modifications RAC - qualitative and quantitative. Cm. also Wasserman reaction, Serological studies.

Board - Zhang reaction [J. Bordet, O. Gengou; SYN.: the reaction of rejection of complement, the reaction commit alexina (complement), the reaction of binding complement (RAC)] - immunological response, based on the property of the complex antigen-antibody capture free complement. RAC occurs in 2 phases: 1) adsorption of antibodies to antigens, 2) the expression reaction (bacteriosis or hemolysis), which requires the presence of complement. Dependence bacteriolytic reactions from the presence of complement allows to reveal the interaction of antibodies and antigens in the reaction Board - to Zhang. The index of conformity of antibodies in this reaction is the complement fixation relevant immune systems identified added to the reaction mixture "indicator" haemolytic system.
The reaction of the Board - Zhang is carried out in two stages: first, the target antigens and antibodies are placed in conditions providing their interaction in the presence of complement, and after adsorption to analyze the immune system is added haemolytic system (hemolysin + + erythrocytes). In accordance antigens and antibodies is their interaction and who is present in the reaction mixture to complement fixed by the immune system. In this case, adding the indicator system of hemolysis is not happening due to the absence of complement (positive). If the analyzed antibodies are not adsorbed on the antigens, complement in the reaction mixture remains free and adding haemolytic system is hemolysis (negative reaction).
The principle developed by the Board and Zhang method serological analysis formed the basis of numerous modifications of the reaction used in diagnostic practice and research work.
Ordinary RAC, which is registered 100% lysis of erythrocytes, requires the pre-titration complement; the latter is added to the immune system at a dose of not more than is required for hemolytic reactions. Scheme of setting reactions are determined by its purpose. The experience may be tested different doses of antigen with constant content of serum and complement, various dilution of serum with regular doses of antigen and complement, and so on Ingredients reactions are: 1) test serum, warmed up for 30 minutes at 56 degrees to inactivate contained therein complement; 2) antigens (which are used suspensions of bacteria extracted from them, proteins, polysaccharides, and other), extracts from the cells of plants and animals, viruses and so on, 3) the presence of complement fresh serum Guinea pigs, 4) haemolytic system (sensitized sheep erythrocytes) - 5% suspension of erythrocytes contacted haemolytic serum within 30 minutes at temperature of 37 degrees.
For cultivation of ingredients used saline solution NaCl. Anticomplementary individual ingredients tested in the control samples. The first phase of reaction (adsorption antibodies) is carried out at temperature 37 deg 60 minutes or at 4-6'c for 18 to 20 hours. (RJC in the cold). In the latter case occurs more full complement fixation, which increases the sensitivity of the method. At the second stage of the reaction mixture is maintained at a temperature of 37 degrees. The result register at the moment 100% of hemolysis in the control samples.
In diagnostic practice to use active, but also "indirect" methods of reaction of binding complement, which modifications reaction Board - to Zhang. In the first indicator of the reaction is change the content of complement in the tested serum. The second is based on the fact that for some diseases the serum does not contain complementative antibodies, but can prevent reactions with serum with complementative activity.
The greatest sensitivity and accuracy inherent in quantitative RAC, which register hemolysis in partial lysis. The sensitivity of this modification reactions Board - Zhang due to the fact that in the Central zone of lysis (20-80%) ratio number of complement to the number lisaruumi of erythrocytes has linear character. In the basis of this reaction is a special method of titration of complement, the number of which is expressed in 50% of the units (SN) and is calculated on the basis of the equation of Krogh, representing the progress of hemolysis in partial lysis.
The degree of hemolysis is set using spectrophotometer or photoelectrocolorimeter.
Quantitative RAC in turn has a number of modifications. In particular, micromethod provides greater accuracy of definitions for low consumption ingredients.