Ehrenberg B, Farkas D L, Fluhler E N, Lojewska Z, Loew L M
Biophys J. 1987 May;51(5):833-7. doi: 10.1016/S0006-3495(87)83410-0.
A potential-sensitive dye was recently used to measure the spatial variation in the membrane potential induced by an externally applied electric field. In this work, we demonstrate that the time course of these induced potentials can also be followed. Two experimental systems were explored. Dye fluorescence from HeLa cells could be modulated by a train of field pulses; the relative fluorescence change measured with a lock-in amplifier was linear with the field and similar to the fluorescence responses obtained in the static measurements. A model membrane system consisting of a hemispherical bilayer allowed convenient measurement of the dye absorbance change as a function of the bathing solution conductivity. The charging time of the membrane was inversely related to the aqueous conductance as predicted by the theoretical solution to Laplace's equation.
最近，一种电位敏感染料被用于测量外部施加电场引起的膜电位的空间变化。在这项工作中，我们证明了这些诱导电位的时间进程也可以被追踪。我们探索了两个实验系统。来自HeLa细胞的染料荧光可以被一系列场脉冲调制；用锁相放大器测量的相对荧光变化与场强呈线性关系，并且与在静态测量中获得的荧光响应相似。由半球形双层组成的模型膜系统便于测量染料吸光度随浴液电导率的变化。膜的充电时间与水相电导率成反比，这与拉普拉斯方程的理论解所预测的一致。
