ABSTRACT
Hanstein introduced the term protoplast in 1880 to designate the living matter enclosed by plant cell membrane. The isolated protoplast is unusual because the outer plasma membrane is fully exposed and is the only barrier between the external environment and the interior of living cell. Protoplasts are not only useful for cell fusion studies but, these can also take up, through their naked plasma membrane foreign DNA, cell organelles, bacteria or virus particles. Protoplasts are isolated by mechanical and enzymatic methods. During the enzyme treatment, the protoplasts obtained need to be stabilized because the mechanical barrier of cell wall which offered support has been broken. For this reason an osmoticum is added which prevents the protoplasts from bursting. Isolated protoplasts are usually cultured in either liquid or semisolid agar media plates. Protoplasts are sometimes allowed to regenerate cell wall in liquid culture before they are transferred to agar media.
