StacksVerified U.S. regulatory reference

21 CFR §866.5775

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
  1. (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.
  2. (b)Classification. Class II (performance standards).