Semi-solid surface fluorometric analysis of glucose.

We describe an enzymatic fluorometric method for determining glucose concentrations in blood samples by analysis on a semi-solid surface (silicone-rubber pads). The method is an adaptation of existing spectrophotometric procedures based on the sequential coupling reactions with glucose-6-phosphate dehydrogenase and NADP+. The rate of appearance of NADPH fluorescence at 460 nm (excitation wavelength, 340 nm) is monitored and related to the glucose concentration in plasma or serum. The calibration curve is linear to 2.50 g/liter. The chief advantages of this method over the spectrophotometric procedure are low cost and rapid response. The results obtained correlate well with those of the o-toluidine method (correlation coefficient, 0.986).