An improved dinitrosalicylic acid method for determining blood and cerebrospinal fluid sugar levels

A development of a technique for estimating sugar in blood, cerebrospinal fluid, etc., is described, using 3:5-dinitrosalicylic acid (D.N.S.A.) originally introduced by Sumner (1921). Results can be obtained in less than 10 minutes if required. The method is well suited to the estimation of random blood sugars and the handling of diabetic clinic requirements in hospital laboratories. The reagents are cheap, stable, and easily prepared. The results are very close to true glucose values in blood and cerebrospinal fluid. The technique has justified its existence in a busy clinical laboratory on the grounds of simplicity and rapidity, and is sufficiently precise for all ordinary work.