An electroporation chamber is provided wherein cells are borne by a fluid medium through a conductive mesh receiving electrode (with the mesh size being such that it allows passage of cells of the desired size/type) and into the chamber. The cells are then captured on a conductive mesh capturing electrode having a mesh size which retains the desired cells. The electrodes are then charged to effect electroporation or other operations within the captured cells between the electrodes. If desired, different fluid media may flow through the electrodes and chamber (and over the cells) during such activities. When operations are completed, fluid flow may be reversed to carry the treated cells back out of the chamber through the receiving electrode.