Section 866.4100 - Complement reagent(a)Identification. A complement reagent is a device that consists of complement, a naturally occurring serum protein from any warm-blooded animal such as guinea pigs, that may be included as a component part of serological test kits used in the diagnosis of disease.(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 .47 FR 50823, Nov. 9, 2001, as amended at 66 FR 38792 , July 25, 2001