Hemoglobin A 2 assay.

(a) Identification. A hemoglobin A 2 assay is a device used to determine the hemoglobin A 2 content of human blood. The measurement of hemoglobin A 2 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]