Urinalysis - The Carter Center

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Types of Urinary Sugar ( Glucose )Tests
• Test for urine sugar is used to detect diabets mellitus and also
used to monitor the effectiveness of diabetic control.
• There are various tests for glucose which may be applied to
urine. The most frequently used are :
a. Non specific reduction tests based on the reduction of
certain metal ions by glucose;
b. Enzymatic tests based on the action of glucose oxidase on
glucose.
Non- Specific Tests for Glucose
These tests are based on the ability of glucose to act as reducing
substances. Tests that are based on the reducing ability of glucose, are
not specific for glucose. In these tests, glucose is acting as a reducing
agent, and any compound with a free aldehyde or ketone group will give
the same reaction. Hence Glucose is not the only reducing substance
that may be found in urine. Urine contine nonglucose reducing
substance (NGRS) such as: uric acid, creatinine, galactose, fructose,
lactose, pentose, levulose, homogentisic acid, ascorbic acid, chloroform,
and formaldehyde.
Commonly used non-specific tests for urinary sugar are Benedict's
Qualitative Test and the Clinitest Tablet Test.
A. Benedict's Qualitative Test
Benedict is a very sensetive copper reduction test and may give
positive reactions with non-specific non-glucose reducing substances
normally present in urine. Since glucose is the reducing agent, it is
oxidized to gluconic acid. The positive reaction is indicated by a color
change. It is a qualitative test in which the degree of color formation is
proportional to the amount of reducing substance present in the