O Antigens

**Definition:** The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

**Tree numbers:** - D09.698.718.450.600 - D10.494.600 - D23.050.161.616.525.600 - D23.946.123.329.500.600

**Synonyms:** - O Antigen, Bacterial - O Antigen - O-Antigen - O-Specific Polysaccharide - O-Specific Polysaccharides - O-Antigens