DEVELOPMENT OF A HOMOGENEOUS IMMUNOASSAY FOR MEASURING HEMOGLOBIN A1C

The Tina-quant(R) Hemoglobin A1c (HbA1c) Assay by Boehringer Mannheim GmbH has been applied to several routine clinical chemistry analyzers. They have been evaluated in the United States by both Microgenics and Boehringer Mannheim, Indianapolis. The assay is a two channel method for the immunologic determination of % HbA1c. The two channels consist of the absolute determination of HbA1c and the determination of total hemoglobin in g/dl. The determination of HbA1c by the Tina-quant meth od is based on the Tinia principle (Turbidimetric Inhibition Immune-as say). The antibody of the assay is specific for the glycated amino-ter minus of the hemoglobin beta-chain. Excess antibodies that do not bind to the HbA1c epitope form agglutinated complexes with a polyhapten pr esent in the R2 reagent. Agglutinated complexes are measured turbidime trically. The greater the signal that is produced, the lower the conce ntration of HbA1c. The determination of total hemoglobin is a one reag ent clinical chemistry that is cyanide free. After the sample is hemol yzed, the released hemoglobin is converted into a derivative that is m easured photometrically at 600 mm. Tina-quant(R) HbA1c is an efficient and cost effective method for the determination of % HbA1c. It has be en applied and evaluated on several clinical analyzers, including BM/H itachi 704/717/ 911, Roche COBAS Mira, and the Beekman Synchron CX. Th e assay is fully automated with ready to use reagents. It is precise a nd exhibits good correlation to conventional HPLC methods.