Section 866.5330 - Factor XIII, A, S, immunological test system(a)Identification. A factor XIII, A, S, immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the factor XIII (a bloodclotting factor), in platelets (A) or serum (S). Measurements of factor XIII, A, S, aid in the diagnosis and treatment of certain bleeding disorders resulting from a deficiency of this factor.(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 § 866.9 . This exemption does not apply to factor deficiency tests classified under § 864.7290 of this chapter.47 FR 50823, Nov. 9, 1982, as amended at 65 FR 2312 , Jan. 14, 2000