Q.Write the various steps involved in cell suspension culture.

Cell suspension culture is established by inducing a friable callus, transferring it into agitated liquid medium, and repeatedly subculturing the resulting free cell/clump suspension.

Cell suspension culture is a technique for growing plant cells as free (or loosely clumped) cells dispersed in a liquid nutrient medium, rather than as an organised solid mass. The steps involved are:

1. Induction of friable callus: an explant is first cultured on a solid (agar-gelled) nutrient medium containing appropriate plant growth regulators, to induce the formation of a callus (an unorganised mass of dedifferentiated cells). For suspension culture, a soft, loosely-organised, easily-crumbling ('friable') type of callus is specifically selected, since it breaks apart readily into small cell clumps when transferred to liquid.
2. Transfer to liquid medium: small pieces of this friable callus are transferred into a flask containing liquid nutrient medium (essentially the same nutrient composition as the solid medium, but without the gelling agent).
3. Continuous agitation: the flask is placed on a rotary/orbital shaker, kept in constant, gentle motion. This agitation serves two purposes -- it keeps the cells and small cell aggregates evenly dispersed throughout the liquid rather than settling, and it ensures adequate aeration (oxygen exchange) for the actively dividing cells. …