B. Flagellum It is the organ of locomotion in bacterial cell and consists of thee parts. These are .The filament . The hook . The basal body The basal body and hook are embedded in the cell surface while the filament is free on the surface of bacterial cell. Their presence in bacterial cell is detected by
. Hanging drop preparation . Swarming phenomenon on surface of plate agar . Motility media . Special staining methods . Silver impregnation methods . Dark –field microscopy . Electron microscopy Size: 3-20μm in length and 0.01-0.013μm in diameter. It is composed of protein named as flagellin. The flagellar antigen in motile bacterium is named as H (Hauch) antigen.