Patch-Clamp Recordings in Adherent Cells

Shortly before the measurements, cells (e.g., GH₃ or HEK293T cells) were harvested and transferred to a homemade recording chamber positioned on the fixed stage of an inverted Olympus fluorescent microscope (CKX-41; Yuan Yu, Taipei City, Taiwan). Cells were put into in normal Tyrode’s solution at room temperature (22 to 25 °C). After cells were left to adhere to the bottom for several minutes, the recordings were performed. Patch-clamp experiments under either whole-cell, cell-attached, or inside-out mode were achieved with either an RK-400 (Biologic, Claix, France) or an Axopatch-200B amplifier (Molecular Devices, Sunnyvale, CA) [16 (link),35 (link)]. We fabricated patch pipettes, the resistance of which was around 3 to 5 MΩ, from Kimax-51 borosilicate capillaries (#34500; Kimble; Dogger, New Taipei City, Taiwan) pulled on either a PP-830 vertical puller (Narishige, Major Instruments, New Taipei City, Taiwan) or a P-97 programmable horizontal puller (Sutter Instruments, Novato, CA, USA), and the pipettes were then fire polished with an MF-83 microforge (Narishige). During measurements, the digitized signals, consisting of voltage and current tracings, were stored online at 10 kHz in an ASUSPRO-BU401LG computer (ASUS, New Taipei City, Taiwan) controlled by pCLAMP 10.7 software (Molecular Devices).