CFR > Title 9 - Animals and Animal Products > CHAPTER I—ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE > SUBCHAPTER E—VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS (parts 101 to 124) > PART 101—DEFINITIONS > 101.7—Seed organisms.

101.7—Seed organisms.

When used in conjunction with or in reference to seed organisms, the following shall mean:
(a) Master Seed. An organism at a specific passage level which has been selected and permanently stored by the producer from which all other seed passages are derived within permitted levels.
(b) Working Seed. An organism at a passage level between Master Seed and Production Seed.
(c) Production Seed. An organism at a specified passage level which is used without further propagation for initiating preparation of a fraction.

Code of Federal Regulations

[49 FR 22625, May 31, 1984]