Yamaguchi H
Can J Physiol Pharmacol. 1987 May;65(5):1006-8. doi: 10.1139/y87-159.
A novel concentric design of double-barrelled Ca2+-selective microelectrode, with an inner pipette tip that protrudes beyond an outer one, has recently been developed and is described. This configuration of pipettes was produced from concentric capillaries in one step using a horizontal pipette puller. For the tip of the inner barrel to protrude, Corning 1724 aluminosilicate glass was selected, as it has a higher melting point than the 1723 glass which is used for the outer barrel. To reduce electrode resistance the inner capillary was best made with a triangular shape. It was preferentially silanized in a dry box by injection of methyltrichlorosilane into only the inner barrel. The Ca2+ neutral carrier-based liquid membrane (ETH 1001) was back-filled from the tip to the shank of the inner pipette and above this CaCl2 solution was added. KCl, which contained EGTA and was buffered to pCa 7, was used to fill the reference barrel. These Ca2+ electrodes showed linear response with slope approximately equal to 30 mV for changes in Ca2+ concentration between 10(-3) and 10(-7) M in the presence of constant [K+]. They offer a number of advantages including a low noise level achieved by the presence of the external concentric KCl electrode, and a simple mechanical structure that allows applications to a variety of small cells.
最近开发并描述了一种新型的双管钙离子选择性微电极同心设计，其内部移液器尖端伸出外部尖端。这种移液器配置是使用水平移液器拉拔器一步从同心毛细管中制造出来的。为了使内管尖端伸出，选择了康宁1724铝硅酸盐玻璃，因为它的熔点比用于外管的1723玻璃更高。为了降低电极电阻，内毛细管最好制成三角形。它优先在干燥箱中通过仅向内管中注入甲基三氯硅烷进行硅烷化处理。基于钙离子中性载体的液膜（ETH 1001）从内移液器的尖端到柄部进行回充，并在该氯化钙溶液上方添加。含有乙二醇双四乙酸（EGTA）并缓冲至pCa 7的氯化钾用于填充参比管。在恒定[K⁺]存在的情况下，这些钙离子电极对10⁻³至10⁻⁷ M之间的钙离子浓度变化显示出线性响应，斜率约为30 mV。它们具有许多优点，包括外部同心氯化钾电极的存在实现了低噪声水平，以及简单的机械结构，允许应用于各种小细胞。
