水晶振動子マイクロバランス法を用いる溶液中タンパク質定量における高感度化手法の検討

抄録

The frequency fluctuation of a quartz-crystal microbalance (QCM) measurement obtained in the gas phase is significantly smaller than that obtained in the liquid phase. This work has tried to enhance the sensitivity of the QCM measurement of a protein by drying a sample previously bonded at a Au electrode surface on the quartz crystal in the liquid phase. In this method, argon or nitrogen gas was flowed for 25 minutes to dry the sample; excellent stability of the background fluctuation of frequency was obtained. In order to illustrate the present method, albumin, lactate dehydrogenase and monoamine oxidase were chosen as analytes. The linear relationships between the amount of each protein and the frequency changes were obtained below 2.0 μg. Then, anti-bovine albumin was measured using a bovine albumin-immobilized quartz crystal. It was found that the calibration curve of anti-bovine albumin showed a linear line over a weight range from 0.1 to 1.0 μg. The present method requires only a small sample volume, and is able to determine the amount of protein without dilution.