Cell membrane electropermeabilization with arbitrary pulse waveforms.

We present a detailed design of a system for in vitro electropermeabilization with arbitrary waveforms. A low-voltage signal is generated by a programmable function generator and amplified by a bipolar amplifier circuit built from commercial components. We describe the general outline of the setup, give the scheme of the amplifier circuit, and present the frequency characteristics of the system. Unlike the commercially available devices used for electropermeabilization, the system presented in this article provides a custom choice of the pulse waveform, with the amplitude from 0 up to 260 V (520 V peak-to-peak) with a shape distortion below 5% for the band from 500 Hz up to 35 kHz, and below 15% up to 55 kHz. The circuit can deliver currents up to 5.2 A, which, at the maximum output voltage, is obtained on a resistive load of 50 W. For larger loads (lower resistivity), the performance of the circuit is reduced, with a possibility of malfunction. The total cost of the amplifier circuit components is less than US$400, and with programmable function generators starting at approximately US$1,000, this makes the presented design attainable to any laboratory with interest in electropermeabilization.