Design and Construction of Slide Based Electroporator for Research Applications

Abstract

Electroporation is a significant increase in the conductivity and permeability of the cell plasma membrane caused by an externally applied electric field.This technique is widely used for genetic transfection of a wide array of cells for research as well as commercial applications. Though a large number of Electroporation devices are in market, they are expensive and one has to go for cumbersome work flow for transfection of cells. In the current project, a miniature slide based Electroporator was designed and fabricated to minimize the cost and work flow during cell transfection protocols in laboratories. Briefly, a circular well (25 mm diameter and 14 mm depth) was fabricated by exclusion in a thick glass slide for housing live cells in suspension. The well was connected to copper electrodes for supplying electrical pulse of high voltage and of low duration. A pulse generator was developed where a train of low amplitude pulses were generated using 555 Timer and stabilized by 7805 Regulator. A Microcontroller, 89C52 was used to control the number of pulses. A transformer with 1:100 turns ratio was used to amplify a pulse with amplitude of 9 V to 700-900 V, necessary for cell membrane poration without damaging the live cells. The pulse generation system was connected to the copper electrodes in contact with the cell suspension in glass well. The Electroporation system could generate pulses with maximum amplitude of 782 V and a maximum 20,000 number of pulses per second. Thus, a pulse with duration of 50 µs could be generated with the system which is highly effective for pore formation in the cell membrane without killing the cells. Further, the potentiometer used was able to vary the voltage from 50 V to 782 V while the pulse duration was varied from 50 µs to 1000 ms. Such a wide range of variations in pulse amplitude and duration equips the Electroporator to be applicable for transforming different cell lineages with molecules of different sizes.