Design Your Own Electroporation Protocol Episode 2 - Converting Between Different Gap Sizes
By Michelle M. Ng, Ph. D.
This is the second in a series of posts where we are providing tips for developing or improving your own electroporation method.
Today's post will be short and sweet, as we explore how to convert between two electrodes or cuvettes with different gap sizes.
Gap distance is defined as the distance between electrode contacts or between parallel electrode plates in a cuvette.
Electrical Field strength (expressed as Volts/centimeter or kiloVolts/centimeter) is equal to the voltage (V) set on your electroporator divided by the gap distance between your electrode contacts (cm).
This means that the relationship between gap distance and field strength is inversely proportional; as gap distance increases, electrical field strength decreases.
The simple answer to convert an electroporation protocol for different electrode gap distances is to adjust the voltage such that the field strength (in V/cm) is constant between two different gap sizes, while keeping the other parameters such as pulse length and number of pulses the same.
As an example, if you normally electroporate at 500 V in a 4 mm gap cuvette, then you would want to use 250 V for a 2 mm gap cuvette or 125 V for a 1 mm cuvette; all of these would achieve a final field strength of the same 1250 V/cm.
Note: If the electrode is a different shape or there is a change in the relative volume of your sample, some additional fine tuning may be necessary for best results.
Next time we'll tackle Episode 3 - Scaling Up and Down
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