Section 864.7400 - Hemoglobin A[2] assay(a)Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content of human blood. The measurement of hemoglobin A2 is used in the diagnosis of the thalassemias (hereditary hemolytic anemias characterized by decreased synthesis of one or more types of hemoglobin polypeptide chains).(b)Classification. Class II (performance standards).45 FR 60617, Sept. 12, 1980