Paper strips impregnated with an enzyme, glucose oxidase, can be used to test for the presence, and also to estimate the concentration, of glucose in urine. The accuracy of such estimates was investigated by testing 104 samples made by adding predetermined amounts of glucose to normal urine to give concentrations of 10, 5, 3, 2, 1, 0.5, 0.25, and 0.1%. The test discriminated correctly among these possibilities except in six cases, four 0.25% samples being misread as 0.5% and two 0.1 % samples being misread as 0.25%. The effects of varying the pH, of letting the urine stand at different temperatures, of contaminating it with bacteria, and of exposing the test strips to water, air, and sunlight were studied, as were the responses of the strips to solutions of other sugars (maltose, fructose, and galactose). The test was found to be specific for glucose. The enzyme must be protected against the destructive action of heat, air, and light. Used with due care, ezpecially with respect to timing, the test discriminates reliably among the above-mentioned concentrations of glucose in urine and is a practical method for observing the course of clinical glycosurias.
Bell WN, Jumper E. EVALUATION OF TES-TAPE AS A QUANTITATIVE INDICATOR. JAMA. 1958;166(17):2145–2147. doi:10.1001/jama.1958.02990170043010
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