{"data":{"id":"us/21-cfr-866.4520","jurisdiction":"us","citation":"21 CFR 866.4520","heading":"Immunofluorometer equipment.","body":"(a) Identification. Immunofluorometer equipment for clinical use with its electrical power supply is a device used to measure the fluorescence of fluorochrome-labeled antigen-antibody complexes. The concentration of these complexes may be measured by means of reflected light. A beam of light is passed through a solution in which a fluorochrome has been selectively attached to serum protein antibody molecules in suspension. The amount of light emitted by the fluorochrome label is detected by a photodetector, which converts light energy into electrical energy. The amount of electrical energy registers on a readout system such as a digital voltmeter or a recording chart. This electrical readout is called the fluorescence value and is used to measure the concentration of antigen-antibody complexes.\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 E—Immunology Laboratory Equipment and Reagents"],"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":"8135130432eba48eeea9023dbc7bfa0fb2cf32c85aaf32e299949c1f00d6df11","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-866.4500","next":"us/21-cfr-866.4540"},"notice":"GroundRules: Original legal text. Not legal advice."}