Micropulser for real-time microscopy of cell electroperturbation

A miniature solid state pulse generator (/spl ap/400 V) is designed for the electroperturbation of biological cells in solution. Design emphasis is placed on compactness and the control over pulse shape with the goal of targeting specific cell responses, including apoptosis. Cell electroperturbation with nanosecond pulses is typically performed on a batch of cells in a cuvette with volume of less than 1 mL. The desire to observe in real time morphological changes and electrical potential gradients necessitates a design appropriate for optical and electrical studies. We describe here a "micropulser" designed to deliver pulses of several hundred volts to a narrow channel of cells on a microscope slide. The pulse generator, based on a single fast power MOSFET, forms square pulses of variable width from 15 ns to DC. The pulse generator unit and slide holder are compact and designed for optical access and monitoring.