Böhle T, Benndorf K
Institut für Vegetative Physiologie, Universität zu Köln, Germany.
Pflugers Arch. 1994 Jul;427(5-6):487-91. doi: 10.1007/BF00374265.
A simple technique of tip preparation in patch pipettes is described, which facilitates giga-seal formation. The pipettes were fabricated from thick-walled borosilicate glass tubing (external diameter 2.0 mm, internal diameter 0.5 mm) and the tips could be repeatedly broken in the bath. The pipette resistance correspondingly fell in steps of 3-20 M omega from about 80 M omega to about 2 M omega (double concentrated Tyrode). Scanning electron microscopy showed that the tip obtained after breaking was fairly plain. These broken tips were especially appropriate for patch-clamping. In cardiac myocytes in 11 out of 26 patches with Na+ channel activity, giga-seals developed spontaneously, i.e. without suction. In these patches the amplitude of the mean current with depolarizing pulses to -40 mV was significantly higher in comparison with patches formed under negative pressure. It is concluded that spontaneously sealed patches are most likely of planar configuration and the Na+ channel activity exceeds that in suction-induced patches.
本文描述了一种用于膜片移液器尖端制备的简单技术，该技术有助于形成千兆封接。移液器由厚壁硼硅酸盐玻璃管（外径2.0mm，内径0.5mm）制成，其尖端可在浴槽中反复折断。移液器电阻相应地从约80MΩ逐步下降3 - 20MΩ，降至约2MΩ（双倍浓缩台氏液）。扫描电子显微镜显示，折断后获得的尖端相当平整。这些折断的尖端特别适合膜片钳记录。在26个具有钠通道活性的心肌细胞膜片中，有11个自发形成了千兆封接，即无需施加吸力。与在负压下形成的膜片相比，在这些膜片中，去极化脉冲至 - 40mV时平均电流的幅度明显更高。得出的结论是，自发封接的膜片很可能是平面构型，并且钠通道活性超过吸力诱导形成的膜片。
