Carbohydrate-deficient transferrin evaluation in dry blood spots

The aim of this study was to assess the performance of the isoelectric focusing/immunoblotting/laser densitometry (IEF/IB/LD) procedure to evaluate carbohydrate-deficient transferrin (CDT) derived from dry blood spots. Serum specimens obtained from insurance applicants were analyzed for CDT by IEF/IB/LD. Dry blood spots derived from 50 serum specimens were analyzed by IEF/IB/LD. A comparative analysis of these serum specimens and the paired dry blood spots by IEF/IB/LD shows a highly significant correlation of the CDT values (r = 0.94, p < 0.0001). Stability studies indicate that, under proper storage conditions (2-3 days at room temperature, 2 weeks at 4 degrees C, or frozen at or below -20 degrees C indefinitely), dry blood spots can be used as a source of CDT for analysis by IEF/IB/LD, thus simplifying sampling, storage, and transportation of specimens to the testing site.