part_subject: "IMMUNOLOGY AND MICROBIOLOGY DEVICES"
subpart_code: "E"
subpart_subject: "Immunology Laboratory Equipment and Reagents"
section_number: "866.4800"
section_subject: "Radial immunodiffusion plate."
cfr_reference: "21 CFR 866.4800"
title_name: "Title 21"
title_subject: "Food and Drugs"
parts_covered: "Parts 800 to 1299"
revised_date: "Revised as of April 1, 2019"
publication_date: "As of April 1, 2019"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
---
(a)Identification. A radial immunodiffusion plate for clinical use is a device that consists of a plastic plate to which agar gel containing antiserum is added. In radial immunodiffusion, antigens migrate through gel which originally contains specific antibodies. As the reagents come in contact with each other, they combine to form a precipitate that is trapped in the gel matrix and immobilized.
(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.