Agglutination is an antigen-antibody reaction in which particulate antigens (e.g., cells, bacteria, or latex beads) clump together in the presence of specific antibodies. This reaction is a visible, rapid, and sensitive method used in diagnostics, blood typing, and microbiology. Agglutination reactions are immunological assays performed in vitro, resulting in the specific reaction between antigens and antibodies. The term “ agglutination ” refers to the clumping or aggregation of particles. Definition of Agglutination When a particulate antigen (agglutinogen) combines with its antibody (agglutinin) in the presence of electrolytes at a suitable temperature and pH, the particles are clumped or agglutinated. Agglutination is the aggregation of already insoluble particles or cells into larger clumps. Interaction between the antibody (Ab) and particulate antigen results in visible clumping called agglutination . Types of agglutination Slide agglutination e.g. Serotyping, blood ... Agglutination is the clumping of particles, such as cells or bacteria, in the presence of an antibody or complement. It is used for blood typing, bacterial identification, and diagnosis of diseases.