Enzymatic determination of isocitrate by amperometric monitoring of the rate of oxygen consumption.

A coupled enzymatic method elaborated for NAD+-dependent dehydrogenases has been adapted for NADP+-dependent isocitrate dehydrogenase, in combination with amperometric measurements. The isocitrate dehydrogenase activity dependent linearly on the isocitrate concentration in the range 0-2 X 10(-4) M. Application of this method affords a sensitive estimation of isocitrate even in turbid liquids such as fermentation broths.