Regulations last checked for updates: Feb 11, 2026

Title 21 - Food and Drugs last revised: Dec 18, 2026
§ 866.5775 - Rheumatoid factor immunological test system.

(a) Identification. A rheumatoid factor immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the rheumatoid factor (antibodies to immunoglobulins) in serum, other body fluids, and tissues. Measurement of rheumatoid factor may aid in the diagnosis of rheumatoid arthritis.

(b) Classification. Class II (performance standards).

authority: 21 U.S.C. 351,360,360c,360e,360j,360
cite as: 21 CFR 866.5775