Which pa of bacteria is most antigenic -

Antigens are usually proteins and polysaccharides, and less frequently, lipids. This includes pas (coats, capsules, cell walls, flagella, fimbrae, and toxins) of bacteria, viruses, and other microorganisms. Lipids and nucleic acids are antigenic only when combined with proteins and polysaccharides. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:88