Evaluation of three minicolumn procedures for measuring hemoglobin A1.

We have evaluated three commercially available column-chromatographic methods (Isolab, Helena, and Bio-Rad) for the determination of "fast" hemoglobin (HbA1). All three methods correlated with HbA1c measurements by "high-performance" liquid chromatography for 121 samples from diabetic patients, with the Isolab method showing the highest correlation (r = 0.921). The Isolab and Helena methods gave results that were linear with proportions of HbA1 as great as 30%; results by the Bio-Rad method were slightly nonlinear at values greater than 15%. The Isolab method showed better within- and between-assay precision (CV) than the other two methods and was considered the simplest to perform by each of four different technologists. We recommend use of the Isolab method over the other two tested and believe that this procedure will be valuable for monitoring long-term glycemic control in diabetic patients.