Comparative study of NBT reduction method for estimation of glycated protein (serum fructoseamine) with glycated HbA1c estimated on DCA 2000+Analyzer (immunoagglutination inhibition).

Glycated protein estimation is a diagnostic tool, used for the long term and short term monitoring of the glycemic status of diabetic patients. The present study is designed to compare and correlate modified NBT reduction method for the estimation of Glycated protein (serum fructosamine) with HbAlc estimated on DCA+2000 Analyzer. Glycated protein (serum fructosamine) reduces Nitro Blue Tetrazolium (NBT) reagent in alkaline medium to tetrazinolyl radical NBT+ which forms a highly colored monoformazen compound, absorbance of which is directly proportional to the concentration of glycated protein (serum fructosamine) present in the sample and is recorded as delta A/min. The results of modified NBT were then compared with HbA1c estimated by immunoagglutination inhibition method. Correlation coefficient between HbAlc with serum fructosamine was found to be r = 0.739 using Schimadzu CL-750 spectrophotometer and r = 0.731 using colorimeter. Results of this study were found to be statistically significant P < 0.001. Hence this method could be used for routine monitoring of blood glucose control in diabetics as HbA1c estimation.