Urinalysis - The Carter Center

concentration and acetone in the smallest concentrations. However
most of the tests for ketonuria are most sensitive to the presence of
acetoacetate. There are no simple laboratory tests for β-hydroxybutyric
acid. Most tests react with acetone and acetoacetate or both.
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Types of Tests for Ketone Bodies
A test for ketone bodies should be done routinely on any urine that is
positive for glucose because they appear in the urine of diabetics. Test
for ketones should be done with in 2 hours after collection
Some of the commonly used tests for ketone bodies are the following:-
- Acetest tablet test,
- Acetone powder test,
- Reagent strip tests (Ex. Ketostix),
- Lang's test,
- Rothera's test.
Principle of the Tests
Both acetone and acetoacetate give a purple color with alkaline
sodium nitroprusside. This is the general principle for the tests
mentioned above.
Results - Report the test as positive or negative
A. Rothera's Test for Acetone and Acetoacetate
Procedure
1. To 5 ml of fresh urine, add ammonium sulphate crystals until
saturated (about 1 g.).
2. Add 2 drops of sodium nitroprusside reagent and mix thoroughly.
3. Overlay with ammonium hydroxide solution (28% full strength).