Abstract
The cut-open oocyte Vaseline gap (COVG) technique is a powerful electrophysiological method for the characterization of ion channels. However, traditional amplifiers for COVG are labor-intensive and require significant user expertise. We introduce an innovative, open-source digital amplifier system with high-speed digitization and software-controlled electronics for computer-driven automation. This system compares well to existing commercial systems in terms of conventional specifications of step response (current peak at 25°μs and decay of 36°μstime constant), current noise (1.0 nA at 3 kHz bandwidth), and dynamic range (96.9 dB). Additionally, it unlocks new methods through close integration of the amplifier and software, including machine learning techniques for tuning capacitive compensation waveforms, achieving a 100-fold suppression of mean-squared transient current, and impedance measurement methods to identify system components such as membrane capacitance and electrode resistances. For future extensions, the design has unique attributes such as real-time digital signal processing for feedback; multiple-input and multiple-output; and allows for user customization. By providing open-source access to the circuit board designs, control software, and FPGA code on GitHub, this approach aims to foster cross-disciplinary collaboration and facilitate instrument customization enabling previously inaccessible electrophysiology experiments.