DETERMINATION OF GLUCOSE IN FISH BLOOD: A MODIFICATION OF THE FOLIN–MALMROS MICROPROCEDURE

Abstract
A modification of the Folin-Malmros micromethod is described for the determination of fish blood glucose. A more efficient separation of blood proteins is obtained by precipitating 0.1 ml blood in 10.0 ml tungstic acid. This is followed by hot alkaline reduction of ferricyanide, and colorimetric measurement of a Prussian blue - sodium lauryl sulphate suspension. The method, which eliminates certain difficulties found in other procedures, has been successfully applied in more than a thousand analyses of blood from two species of fish (Opsanus and Ictalurus) having glucose concentrations between 15 and 250 mg per cent.