Toward understanding and curing mental disorders and cancer, a greatly improved system for transfection of neuronal and tumor cells (e.g. astrocytes) by electroporation will be developed. A preliminary prototype has been constructed and experiments with E. coli show that cells and DNA can be drawn up into a novel pipetting electrode assembly, transfected, and ejected in less than five seconds. This is an order of magnitude time savings compared with currently available commercial devices. Because of decreased exposure time to non-culture conditions and handling, this system offers the potential for increased transformation efficiencies, especially for fragile neuronal and tumor cells. Electroporation units on the market today are bulky, expensive, benchtop devices. By redesigning the power supply with an eye on miniaturization, a compact handheld prototype has been developed. Furthermore, this new design will cost substantially less than currently available equipment, bringing high efficiency electrotransformation to even small laboratories that now resort to less effective, more time consuming, chemically induced transformations. During Phase I, biological testing with various waveforms and cell preparation protocols will be used to better understand the basic mechanism of electroporation and Optimize the above designs, with the results to be applied to Phase Il neuronal and tumor cell transformations.