[New formation of fructosamine in patient serum following blood collection].

The stability of fructosamine has been analysed in sera of 24 patients. Fructosamine concentrations increased daily with a constant rate of formation. Synthesis of fructosamine in vitro strongly depended on the incubation temperature and was directly proportional to the glucose concentration of the sample. It is recommended to store sera for the determination of fructosamine at 4 degrees C or - 20 degrees C.