The studies of cells in man have been largely done from dead tissue.

So the heart is an organ made from several tissues.

And one company plans to market cells grown from fetal tissue.

It also takes away waste and carbon dioxide from tissues.

Its main function is to keep white blood cells from damaging normal tissues.

Researchers are trying to identify ways to stop the immune system from damaging tissue in the first place.

The complete state of stress existing from tissues to cells to molecules.

The lungs, of course, had to be re-grown from available tissue.

An unknown quality is missing from dead tissue, the important quality-life.

Samples can be taken from whole tissue or from cell culture.