Electroporation -Indroduction of DNA into cells by exposing them for very brief periods to high voltage electrical pulse which is thought to induce transient pores in the plasma lemma is called electroporation.

There are basically two systems of electroporation:
(1) low voltage-long pulse method and
(2) high voltage-short pulse approach.

For tobacco mesophyll protoplasts, the typical values are as follows: for low voltage long pulse method, 300-400 V cm-l for 10-50 ms (milliseconds; exponential decay), and for the high voltage-short pulse approach, 1000-1500 V cm-l for 10 μs (microseconds; square wave pulse generators).

(1) a heat-shock to protoplasts just prior to electroporation, and the presence of low concentration (about 8%) of PEG during electroporation.
For most species PEG-induced gene transfer is considered to be more reliable and efficient than electroporation. But some plant species are sensitive to PEG for which electroporation may be the method of choice.Electroporation has been used to produce stably transformed cell lines and/or plants in several plant species, e.g., tobacco, petunia, maize, rice, wheat etc.

In case of tobacco, the frequency of transformation was as high as 2-8% (in presence of about 7% PEG). Electroporation has also been used to deliver DNA into intact plant cells.

The cell wall presents an effective barrier to DNA; therefore, it has to be weakened by a mild enzymatic treatment so as to allow the entry of DNA into cell cytoplasm. Electroporation of intact maize and sugarbeet cells resulted in low levels of transient expression; stable integration has not been reported.