[Code of Federal Regulations] [Title 21, Volume 8] [Revised as of April 1, 2001] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR866.2350] [Page 237] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES--(Continued) PART 866--IMMUNOLOGY AND MICROBIOLOGY DEVICES--Table of Contents Subpart C--Microbiology Devices Sec. 866.2350 Microbiological assay culture medium. (a) Identification. A microbiological assay culture medium is a device that consists primarily of liquid or solid biological materials intended for medical purposes to cultivate selected test microorganisms in order to measure by microbiological procedures the concentration in a patient's serum of certain substances, such as amino acids, antimicrobial agents, and vitamins. The concentration of these substances is measured by their ability to promote or inhibit the growth of the test organism in the innoculated medium. Test results aid in the diagnosis of disease resulting from either deficient or excessive amounts of these substances in a patient's serum. Tests results may also be used to monitor the effects of the administration of certain antimicrobial drugs. (b) Classification. Class I. The device is exempt from the premarket notification procedures in subpart E of part 807 this chapter. [47 FR 50823, Nov. 9, 1982, as amended at 54 FR 25046, June 12, 1989]