Agar stabbing method

The inoculum is stabbed into the centre of a semisolid agar deep. Bacterial motility is evident by a diffuse zone of growth extending out from the line of inoculation. The non-motile bacteria will only grow in the soft agar tube and only the area where they are inoculated.

Motility by bacterium is demonstrated in semi solid agar mediumThe medium mainly used for this purpose is SIM medium (SulphideIndoleMotility medium) which is a combination differential medium that tests three different parameters, Sulfur ReductionIndoleProduction and MotilityThis media has a very soft consistency that allows motile bacteria to migrate readily through them causing cloudiness. The inoculum is stabbed into the center of a semisolid agar deep using a sterile inoculating needle.  Bacterial motility is evident by a diffuse zone of growth extending out from the line of inoculation. Some organisms grow throughout the entire medium, whereas others show small areas or nodules that grow out from the line of inoculation. The non-motile bacteria will only grow in the soft agar tube  and only the area where they are inoculated.