Section 864.7375 - Glutathione reductase assay(a)Identification. A glutathione reductase assay is a device used to determine the activity of the enzyme glutathione reductase in serum, plasma, or erythrocytes by such techniques as fluorescence and photometry. The results of this assay are used in the diagnosis of liver disease, glutathione reductase deficiency, or riboflavin deficiency.(b)Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9 .45 FR 60616, Sept. 12, 1980, as amended at 84 FR 71799 , Dec. 30, 2019