What is the structure of a bacterial capsule?

The bacterial capsule is usually a hydrated polysaccharide structure that covers the outer layer of the cell wall, and in most bacteria it is composed of monosaccharides linked together via glycosidic bonds. However, amino acid (peptide) and protein–carbohydrate capsules have also been described.

What structure does the capsule stain look for?

The main purpose of capsule stain is to distinguish capsular material from the bacterial cell. A capsule is a gelatinous outer layer secreted by bacterial cell and that surrounds and adheres to the cell wall. Most capsules are composed of polysaccharides, but some are composed of polypeptides.

What is the structure of a capsule?

The bacterial capsule is a large structure common to many bacteria. It is a polysaccharide layer that lies outside the cell envelope, and is thus deemed part of the outer envelope of a bacterial cell. It is a well-organized layer, not easily washed off, and it can be the cause of various diseases.

What is a bacterial capsule stain?

Capsule stain is a type of differential stain which uses acidic and basic dyes to stain background & bacterial cells respectively so that presence of capsule is easily visualized. Capsule is synthesized in the cytoplasm and secreted to the outside of the cell where it surrounds the bacterium.

What is a positive capsule stain?

A positive capsule stain requires a mordant that precipitates the capsule. By counterstaining with dyes like crystal violet or methylene blue, bacterial cell wall takes up the dye. Capsules appear colourless with stained cells against dark background.

What is the definition of capsule in biology?

In anatomy, a capsule refers to the membranous sheath that surrounds a bodily organ such as kidney, or the fibrous tissues that surrounds a joint. In botany, a capsule is a dehiscent fruit which, at maturity, split apart (dehisce) to release the seeds within.

What is a capsule in biology?

(pathology) An encapsulated material, especially one that results from a cellular or immune response to a foreign body. Supplement. In anatomy, a capsule refers to the membranous sheath that surrounds a bodily organ such as kidney, or the fibrous tissues that surrounds a joint.