Section 862.1240 - Cystine test system(a)Identification. A cystine test system is a device intended to measure the amino acid cystine in urine. Cystine measurements are used in the diagnosis of cystinuria (occurrence of cystine in urine). Patients with cystinuria frequently develop kidney calculi (stones).(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 § 862.9 .52 FR 16122, May 1, 1987, as amended at 65 FR 2305, Jan. 14, 2000