A New Automated Enzymatic Method for Determination of Blood Glucose by Coupling of Cupric Histamine System

Abstract

A new automated enzymatic method for the determination of glucose In blood or plasma is presented. The procedure employs the cuprlc-histamine complex instead of peroxidase and is based on the measurement of indigo carmine discolored by hydrogen peroxide which is derived from the first enzymatic reaction between glucose and glucose oxidase.
Bacause of a competition between chromogen and naturally occurring oxidizable substances, particularly uric acid, the present method employs glucose solutions containing 5mg/100ml of Uric acid as the standard solutions.
Plasma glucose concentrations determined by this method do not differ statistically from those obtained by two reference methods of glucose (manual enzymatic method and automated alkaline ferricyanide method).
Recovery experiments gave mean yield of 102% and intra-runprecision was about 1.4% (C. V.). Fasting blood glucose levels from 95 normal subjects aged 20-48 years were in range 63-100mg/100ml.
Emphasis is given to the necessity of finding a more specific automated method other than the alkaline ferricyanide method which is still widely preference in clinical laboratories for glucose estimation.