Enzymatic fluorometric microplate assay for quantitative analysis of 3-hydroxybutyric acid in mouse plasma

3-Hydroxybutyric acid (3HB) is a ketone body and acts as an indicator of energy balance and a central regulator of energy homeostasis. We report the application of a sensitive fluorometric assay for the quantitative determination of 3HB. The assay is based on the oxidation of 3HB by 3HB dehydrogenase and on the diaphorase-resazurin amplifying system. This simple assay enables the measurement of changes in 3HB levels in the blood of normal mice by very small volume sample collection. Therefore, this assay will be useful for in vivo studies of small animals.