A Micro Time Method for Determination of Reducing Sugars, and Its Application to Analysis of Blood and Urine

The author and Van Slyke (5) have recently published a method for sugar determination in which the time required to decolorize a standard ferricyanide solution was used as a measure of the sugar content. The convenience which this method demonstrated in clinical work stimulated attempts to widen its range of usefulness by developing a micro modification. By carrying out the reaction in small test-tubes heated in a porcelain casserole, which provides a brilliant white background, it has proved possible without decrease in accuracy to make duplicate determinations on a 0.2 cc. sample of blood. We regret that at the first publication of the time method (5) we overlooked the fact that Cole (1) had previously employed for urine analysis the principle of measuring sugar content by the time required for reducing a colored reagent.l The latter was a copper solution, and has apparently not been adapted to the small amounts of sugar encountered in blood.