Electroporation is the process of introducing foreign DNA into biological samples by applying an electric field to trigger DNA uptake thus allowing for ectopic expression studies. One of the tools that we have been using in our lab for this process is the Genepaddle Electrodes that have been recently developed by BTX. This electrode is compatible with a variety of BTX generators and has been specifically designed for in vitro mouse embryo gene delivery by electroporation.
The BTX Genepaddles are gold plated, non-invasive electrodes consisting of a couple of rectangular paddles (available in either 3 x 5 mm or 5 x 7 mm size, each with a thickness of 1 mm). They are attached to a plastic holder that allows every possible adjustment and orientation of the electrodes, with an inter-electrode gap ranging between 1 and 10 mm. The electric capabilities are a voltage range of 1-200 V (DC) and a pulse length range of 1-99 msec. In addition to the holder, the Genepaddle electrodes may require the purchase of a high voltage banana cable to connect them to the power supply. Altogether the electrodes plus the holder and the connecting cable are relatively expensive, however, it is worth noting that they are reusable at will.
I have used the BTX Genepaddles, in conjunction with the BTX ECM 830, mostly to deliver exogenous DNA into mouse skeletal muscle. Some constructs, including GFP-fusion proteins and LacZ expression vectors, were successfully delivered into the Tibialis anterior muscle with minor damage to the tissue (damaged fibers are easily recognizable under the microscope). For this application I used the smaller paddles (3 x 5 mm), which are small enough that they can be easily placed on the sides of even very tiny muscles such as the Soleus. I compared the electroporation efficiency with a different BTX electrode, namely the 2-Needle Array, and found the 2-Needle Array slightly better for skeletal muscle, although the Genepaddles have the advantage of being non-invasive. Both electrodes worked with as little as 20ug of plasmid, even though published reports using this technique used as much as 50ug of DNA (for electroporating the Tibialis anterior muscle).
In conclusion, the BTX Genepaddles represent an all-new model of electrodes that fills a gap in the BTX product line. Their peculiar composition and shape allow a wide range of applications (i.e. from embryo to organ electroporation). Therefore, the Genepaddles are one of the most interesting new products in the field of in vivo electroporation.
Dario Coletti, PhD
Post-Doctoral Fellow
Mount Sinai School of Medicine, New York