Monitoring the levels of ketone bodies in the urine via nitroprusside reagents provides a semi-quantitative measure of

• A. Acetoacetate
• B. 3-b-Hydroxybutyrate
• C. Acetone
• D. All three ketone bodies

Answer: (A)

The nitroprusside ketone test in urine is specific for acetoacetate. The reagent forms a colored complex with acetoacetate in a basic medium, and the intensity of that color correlates with how much acetoacetate is present, giving a semi-quantitative readout. 3-hydroxybutyrate doesn’t react with nitroprusside, so its level isn’t reflected by this test, and acetone is not reliably detected by this method. Therefore, this assay best measures acetoacetate levels in urine.