The multidisciplinary use of cell, tissue and organ culture techniques, and the attendant use of terms in an ever widening sense, has made it necessary to bring together those terms most often used by scientists employing these techniques. Thus, the Tissue Culture Association Terminology Committee publishes the following integrated listing in an attempt to avoid the confusion which arises when scientists of different disciplines give more than one definition to a particular term or use more than one term to describe the same phenomenon.