Motility Testing – Hanging Drop Method and Stab

Abstract

The mobility in bacteria is largely credited to presence of large hair-like appendages over the body called as ``flagella.'' These are the locomotor organ of bacteria. The process of staining the flagella is very tedious. Also it is very difficult to observe in the normal compound microscope. Bacterial movement must be distinguishable from the ``Brownian movement'' (the movement of small invisible particles in any medium). However, the presences of bacteria/activity of flagella can be visualized by the ability of microbe to move in growth medium or by hanging drop technique.