Oc 725c voltage clamp amplifier

CFTR Cl⁻currents were recorded in ND96 bath solution that contained (in mM): 96 NaCl, 2 KCl, 1 MgCl₂, and 5 HEPES (pH 7.5) in the presence of a maximal CFTR activation cocktail, forskolin (10 μM; adenylate cyclase activator) and 3-isobutyl-1-methylxanthine (1 mM; phosphodiesterase inhibitor). Glass microelectrodes backfilled with 3 M KCl had resistances of 0.5–2 MΩ. Data were filtered at 1 kHz and digitized at 10 kHz using a Digidata 1322 A controlled by the pClamp 9.2 software (Molecular Devices, USA). CFTR currents were elicited using 5 mV voltage steps from −60 to +35 mV using an OC-725C voltage clamp amplifier (Warner Instruments, USA). Oocytes where the CFTR Cl^- current reversed positive of −20 mV were discarded. Clampfit 9.2 software was used for current analysis. All values are presented as mean ± SEM.

TEVC was performed as described before extensively (Pless et al., 2011 (link); Pusch et al., 1995 (link)). In brief, voltage-clamped chloride currents were recorded in ND96 solution (in mM: 96 NaCl, 2 KCl, 1.8 CaCl2, 1 MgCl2, 5 HEPES, pH 7.5) and sodium currents in standard Ringer (in mM: 116 NaCl, 2 KCl, 1 MgCl2, 0.5 CaCl2, 5 HEPES, pH 7.4) using an OC-725C voltage clamp amplifier (Warner Instruments, Hamden, CT). For Iodide exchange experiments of ClC-0 currents, NaCl was substituted by NaI equimolar. Glass microelectrodes backfilled with 3 M KCl had resistances of 0.5–3 MΩ. Data were filtered at 1 kHz and digitized at 10 kHz using a Digidata 1322A (Molecular Devices, Sunnyvale, CA) controlled by the pClamp 9.2 software (Molecular Devices, Sunnyvale, CA). Chloride currents were elicited by +20 mV voltage steps from −120 mV to +80 mV preceded by a +80 mV pre-pulse from a holding potential of −30 mV. Sodium currents were elicited by a 50 ms test pulse to −20 mV from a holding potential of −120 mV. Clampfit 9.2 software was used for current analysis. Numbers of oocytes and batches used, details on current analysis and statistical significance of effects are indicated in the appropriate figure legends or the main text.