Dictyostelium discoideum Electroporator

Easily constructed by investigators with no electronics knowledge, we present an inexpensive and open-source electroporation apparatus for Dictyostelium discoideum with all functional modules and peripherals from Cauchy et al., 2022, "A Low-cost Electroporator for Genetically Modifying Social Amoeba Dictyostelium discoideum" submitted to Journal of Open Hardware. Description: Electroporation to introduce DNA into cells is a common technique in genetic engineering. Dictyostelium discoideum is a well-established eukaryotic model organism that is frequently genetically modified (transformed). We present here an electroporator capable of high efficiency transformation. Our electroporator consists of a high voltage power supply, pulse generator circuit and cell sample cuvette chamber. The power supply is programmed to deliver desired voltage, which when activated by a double-pole, double-throw switch (DPDT) charges a capacitor. Further switching allows the charged capacitor to deliver a precise, consistent exponential decay wave of the proper duration to the cuvette containing a D. discoideum cell and DNA mixture. The high-voltage circuit is housed in an electrically insulated enclosure - we chose a plastic electrical junction box with appropriate holes for switch mounting and cables to pass. A 3D printable cuvette holder was designed and is available in .stl, .dwg and .iges formats. An inexpensive 1,000-volt digital multimeter was integrated into the design to aid in development and testing. To provide hands-free monitoring of the real-time capacitor voltage, we connected multimeter test leads to the capacitor poles. In addition to the standard build, we present here an alternative design for the pulse generator, which we will refer to as "modular". The standard pulse generator was designed to be durable for repeated use in multiple D. discoideum electroporation experiments. This design includes a soldered padboard with high power rated components. The modular pulse generator is designed for ease of build, is easily modified by swapping components for alternative waveforms, and is intended for a small number of electroporations and not routine or repeated use