agglutination reaction

Agglutination reaction

A reaction in which suspended particles are aggregated or clumped. It occurs upon the admixture of another type of particle, a change in the composition of the suspending fluid, or the addition of a soluble agent that acts as a bridge between two or more particles. The reaction is a secondary one in that the process resulting in agglutination occurs after the primary antigen-antibody linkage has taken place.

The particles undergoing agglutination may be either unicellular or microscopic multicellular organisms (such as bacteria and parasites), individual cells of multicellular organisms (such as erythrocytes and lymphocytes), or artificial particles (such as beads of plastic, glass, or polysaccharide). The immunological specificity of agglutination depends upon the uniqueness of the reaction between a marker substance on one type of particle and a receptor on either another type of particle or a specific antibody in solution. The marker can be a usual biological component of the surface of the particle or blood group substance on red cells. It can be an enzymatically or a chemically modified chemical group on the surface of biological particles. It can also be an adsorbed or a chemically attached substance. The attachment can be to biological particles or artificial ones. The receptor can be a biological component of the particle, an attached antibody, or antibody in solution. A reverse reaction is one in which the antibody is attached to a particle and the addition of the antigen causes the mixture to clump. Inhibition of agglutination can also be used to test for antigens, especially of low molecular weight, in a manner similar to that for agglutination itself. See Antigen-antibody reaction, Immunoassay

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.

agglutination reaction

[ə‚glüt·ən′ā·shən rē′ak·shən]
Clumping of a particulate suspension of antigen by a reagent, usually an antibody.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Now when the red cell suspension of the same blood group, is added to the mixture and there will be an agglutination reaction. Thus, in case of non-secretors, there will be agglutination.
Antigens stored at -20AdegC and 25AdegC showed visible agglutination up to 90 and 30 days post preservation respectively in presence of both preservatives thimerosal sodium and sodium azide, separately, while no change in agglutination reaction was observed for antigen stored at 4AdegC throughout the whole storage period of 6 months.
The antiglobulin test is a method of demonstrating the presence of antibody or complement bound to red blood cell (RBC) membranes by the use of anti-human globulin to form a visible agglutination reaction. The IAT tests for antibodies circulating in the patient's plasma, while the DAT tests for antibodies or complement bound directly to the patient's RBCs, indicating in vivo sensitization.
As shown in Table 1, laboratory tests were white blood cells 7.2 x [10.sup.9]/L, platelets 180 x [10.sup.9]/L, hemoglobin 131 g/L, erythrocyte sedimentation rate (ESR) 19 mm/h, C-reactive protein (CRP) 10 mg/L, monotest negative, alanine aminotransferase (AST) 62 U/L, positive Wright agglutination reaction (title 1/1280), and negative Rose Bengal.
Multiple OTf PC2 was characterized by the following: Agar Gel Immunodiffusion (AGID), Immunodiffusion Simple Radial Test (IDSR), Rapid Agglutination Reaction (RAR), and ELISA "in-house" and "double-sandwich" tests.
Agglutination Reaction. In 10 small test tubes, the treated samples were diluted 10-fold at 1: 1 ratios, followed by addition of 0.1 mL 2% red blood cells (type A) to each tube.
The results of the agglutination reaction of the sample were observed with the naked eye.
After three minutes, the agglutination reaction was observed by visual inspection macroscopically with a naked eye.
After 24 h, the agglutination reaction was observed by using a magnifying mirror against illumination source.