A simple one-step enzymatic fluorometric method for the determination of glycerol in 20 microliters of plasma.

An assay for the determination of glycerol concentration in blood or other biological materials is described. The method is based on the conversion of glycerol to dihydroxyacetone in the presence of NAD, the reaction being catalysed by the enzyme glycerol dehydrogenase. The NADH which is formed in stoichiometric quantities during the reaction is estimated fluorometrically. In the presence of the ketone-trapping agent hydrazine the reaction can be made to go to completion above above pH 9.0. Using the method described, glycerol can be measured routinely in a 20-microliters sample of serum or plasma. Although the enzyme is known to react with sorbitol and ethanol, the addition of these substances to the reaction mixture had no significant effect on the determination of glycerol.