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Out of curiosity I've applied (common household) sugar + water mixture to a urine glucose test strip and found no change in color. Is the test strip faulty? Is there any other way to confirm that the test strip works?

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  • Welcome to Medical Sciences! Questions here are required to show results of prior research. As described in the help center and this meta post, this demonstrates that you’ve taken the time to try to help yourself, saves us from reiterating obvious answers, and helps you get more specific and relevant answers. Please edit your question with links to or references to what you've found in your search. Otherwise your question may be closed.
    – Carey Gregory
    Nov 19, 2022 at 22:51
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    Note that table sugar is sucrose, not glucose, so it probably doesn't react to sucrose. But I don't know that for a fact, so you might want to begin your investigation there.
    – Carey Gregory
    Nov 19, 2022 at 22:54

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According to Cowart and Stachura (1990 NBK 245):

Techniques for measuring glucosuria are based upon either glucose oxidase (specific for glucose) or copper sulfate reduction (nonspecific: detects reducing substances including glucose, fructose, lactose, pentoses, galactose, homogentisic acid, and ascorbic acid). ... In the glucose oxidase-based technique, hydrogen peroxide is generated and reacts with horseradish peroxidase to produce nascent oxygen. It in turn oxidizes orthotoluidine to produce the blue or purple color that is read. In [some reactions], oxidized orthotoluidine is reacted with the yellow dye tartrazine to produce a greater range of color development

As Carey Gregory notes in the comments, sucrose is a dimer of glucose and fructose. Thus, to react with glucose oxidate, it would first need to be broken down (ie by sucrase).

Regardless, it seems unwise to attempt to mix up a positive control for your medical test equipment from table sugar.

If necessary, use positive controls from vendors with traceable lot numbers and material safety data sheets. For example, this product includes positive controls for glucose (I have no affiliation with the company and cannot confirm it actually works).

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