gnotobiology
[nō′tō-bī-ŏl′ə-jē]
n.
The study of organisms or conditions that are either free of germs or associated only with known or specified germs.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.