Agglutination

Agglutination is a phenomenon bonding suspended in a saline solution microbes or parts of microbial cells, ricketsi, red blood cells with the formation of flakes or small grains, precipitating. There are specific and nonspecific agglutination. Specific agglutination takes place with the participation of three components: agglutinogen (suspended cells), agglutinins (antibodiescontained in the immune serum obtained after the introduction into an organism of an animal or human germs of this kind) and salts (electrolytes), in izotonicescom solution of which is usually put reaction. Often immune serum agglutinate microbes that have not been used for immunization. In accordance with this distinguished group and specific agglutinin. Group agglutinin cause agglutination reaction with various kinds of microbes that have common antigens with microbes used for immunization-specific - only with the type of microbes that was used for immunization.
Agglutination reaction used to determine the species selected microbe and for the detection of antibodies (see) in serum laboratory animals immunized, sick or vaccinated people. Numerous varieties agglutination reactions are important for the diagnosis of typhoid, paratyphoid (see Vidal reaction), typhus, typhoid [Weil - Felix reaction (see), Weigle reaction (see), the reaction with ricketsiosis antigen suspension killed ricketsi], brucellosis and other
Reaction arrangement: in test tubes prepare dilution of serum 1 : 50; 1 : 100; 1 : 200; 1 : 400; 1 : 800; 1 : 1000 and above. In each tube add the same number of microbial suspension. Preliminary reaction accounting produced after 2 hours after placing tubes in a thermostat at the temperature 37 C; final on the following day after keeping vials at room temperature. Evaluation of the results of the reaction is to the naked eye, with the help of a magnifying glass or agglutinative device in which a suspension of microbes and formed lumps or flakes reviewed in rolling eyepiece in transmitted light. A positive reaction celebrate usually by the highest dilution of serum, which came expressed agglutination. Diagnostic value has a positive reaction from the serum of a patient in a dilution of 1 : 200 and above (subsequent increase of the title).
With rapid agglutination reaction (Noble) 0.1 ml five billion suspension of microbes is mixed with an equal volume of the investigated serum dilutions 1 : 10; 1 : 20; 1 : 40 1 : 80 and after 3-5 minutes after adding 0.8 ml 0,85% solution of sodium chloride take into account the reaction. To define the kind of microbe the agglutination reaction set with a set of agglutinating sera, each of which received the immunization animal certain microbes.
When estimated agglutination reaction on a glass slide cause a drop of the suspension of the investigated microbe and drop specific agglutinins sera 1 : 10; 1 : 20. Both drops mixed few minutes and see the result.
Nonspecific (spontaneous) agglutination see sometimes in isotonic (especially common in bacteria, forming a rough colonies - R-form) in connection with the change of physico-chemical properties of the surface structures of the bacteria. Agglutination of red blood cells - see the Hemagglutination. Cm. also Serological studies.