2. Tissue culture of tissues and /or cells separate from the cells. This is typically facilitated by the use of liquid or semi-solid. Tissue culture commonly refers to the culture of animal cells and tissues.

3. In 1885 Wilhelm Roux removed a section of medullar y plate of an embryonic chicken and maintained it in a warm saline solution for several days, establishing the basic principle of tissue culture. In 1907 the zoologist ROSS GRANVILLIE HARRISON demonstrated the growth of frog nerve cell process in a medium of clotted lymph. In 1913,E.Steinhardt,C.Israeli, and RA.Lambert grew vaccinia virus in fragments of guinea pig corneal tissue.

4. In modern usage tissue culture generally refers to the growth of cells from a tissue from a multi cellular organisms in virto. This cells may be cells obtained from a donor organisms. The term tissue culture is often used interchangeably with cell culture. Tissue culture is a important tool for study of biology of cells from multi cellular organisms. It provides an in virto model of a tissue in a wall defined environment which can be easily manipulated and analysed .

5. Plant tissue culture is a practice to propogate plants under sterile condition, often to produce clones of plants. Different techniques often used in plant tissue culture may offer some advantages over the traditional method of propogation including:- 1. The production of exact copies of plants that produce particularly good flowers, fruits, or have other desirable traits. 2. To quickly produce mature plants, etc..

6. Modern plant tissue culture is performed under aspetic conditions under filtered air. Living plant materials from the environment are naturally contaminated on their surfaces with microorganisms, so surface sterilization of starting materials in chemical solution is required .