1) Body of knowledge related to the use of organisms, cells or cell-derived constituents for the purpose of developing products which are technically, scientifically and clinically useful; alteration of biologic function at the molecular level (i.e., genetic engineering) is a central focus.

2) Applied biological science (as bioengineering or recombinant DNA technology).

3) A set of biological techniques developed through basic research and now applied to research and product development. In particular, biotechnology refers to the use by industry of recombinant DNA, cell fusion, and new bioprocessing techniques.