A convenient electrode holder for glass pipettes to stabilize electrode potentials
A convenient electrode holder for glass pipettes to stabilize electrode potentials
复制标题
方便的玻璃移液器电极支架，可稳定电极电位
DOI：
10.1007/s004240050928
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
F. Sachs
中科院分区：
文献类型：
--
作者：
K. Snyder;Alan Kriegstein;F. Sachs
电生理技术需要稳定、可逆的电极才能准确记录。Ag/AgCl电极通常用于膜片钳和细胞内记录移液器，但是当这些电极暴露于无Cl介质时，它们不再可逆，并且可能产生大的，不稳定的偏移电位。我们在这里提出了一个简单的电极支架设计，它提供了电极溶液和含有AgCl颗粒的充满氯化钾的储层之间的液体连接。这允许使用任何成分的电极溶液而不影响电极的可逆性，并且产生的液体结电位很小且定义良好。将AgCl颗粒与移液器进行机械隔离可以提高电极的长期稳定性，因为在更换移液器时不会刮擦AgCl涂层。持卡人的响应时间及其宽带噪声水平与标准持卡人相当。对于实际的实验持续时间，KCl从储液池沿移液管向下扩散在尖端产生的污染可以忽略不计。同样，移液器内容物向储液器的反向扩散也可以忽略不计。
Electrophysiological techniques require stable, reversible electrodes for accurate recording. Ag/AgCl electrodes are commonly used in patch-clamp and intracellular recording pipettes, but when these electrodes are exposed to Cl–-free media they are no longer reversible and may develop large, unstable offset potentials. We present here a simple electrode holder design that provides a liquid junction between the electrode solution and a KCl-filled reservoir containing the AgCl pellet. This allows an electrode solution of any composition to be used without affecting the reversibility of the electrode, and the liquid junction potentials that develop are small and well defined. Mechanical isolation of the AgCl pellet from the pipette improves long-term stability of the electrode because the AgCl coating is not scraped while changing pipettes. The response time of the holder and its wide-band noise levels are comparable to those of standard holders. For practical experiment durations, the diffusion for KCl from the reservoir down the pipette produces negligible contamination at the tip. Similarly, back diffusion of the pipette contents into the reservoir is also negligible.