{"data":{"id":"us/21-cfr-866.5775","jurisdiction":"us","citation":"21 CFR 866.5775","heading":"Rheumatoid factor immunological test system.","body":"(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.\n(b) Classification. Class II (performance standards).","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER H—MEDICAL DEVICES","PART 866—IMMUNOLOGY AND MICROBIOLOGY DEVICES","Subpart F—Immunological Test Systems"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"e681ef8b75602d41402b98cc1b937e16983673ba404368f424acd79a35f6f44d","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-866.5765","next":"us/21-cfr-866.5780"},"notice":"GroundRules: Original legal text. Not legal advice."}