{"data":{"id":"us/21-cfr-866.5540","jurisdiction":"us","citation":"21 CFR 866.5540","heading":"Immunoglobulin G (Fd fragment specific) immunological test system.","body":"(a) Identification. An immunoglobulin G (Fd fragment specific) immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the amino terminal (antigen-binding) end (Fd fragment) of the heavy chain (a subunit) of the immunoglobulin antibody molecule in serum. Measurement of immunoglobulin G Fd fragments aids in the diagnosis of plasma antibody-forming cell abnormalities.\n(b) Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 866.9.","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":"b537835086e8562725f651bc8034e13b262fd49f67d10511a8fb11f2fbeef9b5","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-866.5530","next":"us/21-cfr-866.5550"},"notice":"GroundRules: Original legal text. Not legal advice."}