Novel solid-phase assay of ketone bodies in urine.
This simple dip-and-read color-matching assay measures ketone bodies in urine. The result is matched with any of the seven colors provided in a color chart. The intensity and hue of the color formed depends on the concentration of acetoacetic acid and follows a gradation starting from light purple (0.2 mol/L acetoacetate) to dark purple and finally to dark violet (9 mol/L). The color developed is independent of pH in the range pH 4-9.5, and is stable for at least 1 h. 3-Hydroxybutyric acid produced no color at the concentrations tested (less than or equal to 100 mmol/L), and acetone was detectable only when greater than or equal to 15 mmol/L. The test was compared with the Ames Ketostix assay in subjects who were on restricted-calorie weight-loss programs. The two methods showed good agreement, except that 20% (21/103) of samples that were negative by Ketostix were read as positive by the new method, which may be more sensitive (detection limit = 0.2 mmol/L). Measurement of urine ketones was unreliable (in comparison with measurement of blood or breath acetone) for monitoring the rate of fat loss during a negative calorie balance.
Kundu
S K
SK
Abbott Laboratories, Diagnostics Division, Abbott Park, IL 60064.
Judilla
A M
AM
D006801:Humans; D006863:Hydrogen-Ion Concentration; D006885:Hydroxybutyrates / Q000737:chemistry; D007202:Indicators and Reagents; D007657:Ketone Bodies / Q000652:urine*; D015431:Weight Loss
D006885:Hydroxybutyrates; D007202:Indicators and Reagents; D007657:Ketone Bodies