Martin, A totally trivial comment, but one I could not let pass, being both a biologist and language curmudgeon (lethal combo). "in vitro" literally means "in glass", as "in a test tube or petri dish" (e.g., in vitro fertilization) and is used in opposition to "in vivo" which means "in life". I feel sure that you meant to say "..of the individual while living (in vivo)..." unless I'm really confused by legalese. Ben Benjamin N. Wise, Ph.D. Professor Emeritus Keene State College