VMC 221: Veterinary Immunology and Serology (1+1)

PREREQUISITES FOR AGGLUTINATION

• Particles used as antigens should have size of > 200 – 250 nm and should remain in suspension for a reasonably long time (48 hours minimum).
• Antibody should be directed to the target surface antigen
• Antigen and antibody should be present in optimal proportions
• An electrolyte or buffer is necessary for the reaction
• Agglutination of bacteria as a test to detect presence of bacterial antibody in sera is an important application of the agglutination reaction.
• Many bacteria such as Brucella, Salmonella, Escherichia, Proteus etc. form smooth suspensions in buffered saline.
• When incubated with antibody against surface antigen like those of flagella, capsular material or cell wall components, the bacteria agglutinate to form clumps.
• Agglutination test is also used for identification of bacterial strains using specific antisera.
• Agglutination can be done in slides or in tubes and hence there is the slide agglutination test and tube agglutination test.