Suspension Cultures - Tissues and cells cultured in a liquid medium produce a suspension of single cells and cells clumps of few to many cells: these are called suspension cultures. Liquid cultures must be constantly agitated, generally by a gyratory shaker at 100-250 rpm (revolution per minute), to facilitate aeration and dissociation of cell clumps into smaller pieces.
Suspension cultures grow much faster than callus cultures, need to be subcultured about every week, allow a more accurate determination of the nutritional requirements of cells and are amenable to scaling up for a large scale production of cells and even somatic embryos (SEs).
The suspension cultures are broadly grouped as:
(1) batch cultures,
(2) continuous cultures, and
(3) immobilized cell cultures.