Grinvald A, Fine A, Farber I C, Hildesheim R
Biophys J. 1983 May;42(2):195-8. doi: 10.1016/S0006-3495(83)84386-0.
To improve the sensitivity of fluorescence measurements of electrical responses from small cells and their processes, we have optimized the optical measuring system. The fluorescence intensity from a stained cell was increased 40-fold relative to our previous apparatus. The increased fluorescence intensity permits the use of an inexpensive photodiode (or a photodiode array) that has a approximately 10-fold higher quantum efficiency relative to a photomultiplier. Utilizing the improved apparatus, we optically recorded an action potential of a 2 microns wide neuronal process with a signal-to-noise ratio of approximately 50 (root mean square noise) without averaging. We also report the design of an improved fluorescence voltage-sensitive probe; the fractional change of the fluorescence signal under optimal conditions was 21%/100 mV.
为提高对小细胞及其突起电反应的荧光测量灵敏度，我们对光学测量系统进行了优化。与我们之前的仪器相比，染色细胞的荧光强度提高了40倍。增加的荧光强度允许使用一种廉价的光电二极管（或光电二极管阵列），其量子效率比光电倍增管高约10倍。利用改进后的仪器，我们光学记录了一个2微米宽的神经元突起的动作电位，信噪比约为50（均方根噪声），无需平均。我们还报告了一种改进的荧光电压敏感探针的设计；在最佳条件下，荧光信号的分数变化为21%/100 mV。
