Section 864.7100 - Red blood cell enzyme assay(a)Identification. Red blood cell enzyme assay is a device used to measure the activity in red blood cells of clinically important enzymatic reactions and their products, such as pyruvate kinase or 2,3-diphosphoglycerate. A red blood cell enzyme assay is used to determine the enzyme defects responsible for a patient's hereditary hemolytic anemia.(b)Classification. Class II (performance standards).45 FR 60610, Sept. 12, 1980