An electroporation apparatus has an electroporation probe terminals for linking with electrodes. A foam is injected at the treatment site to displace blood rather than mixing with it, increasing the contact time of a higher concentration of active agent with the tissue and thus resulting in greater efficacy. With foam solutions, a lower concentration of agent can be used to obtain the same therapeutic effect as in their liquid counterpart, reducing the prevalence of side effects associated with higher concentrations. A foam solution compared to an equivalent liquid solution enables more efficient cell electroporation particularly where bipolar pulses have been employed by mitigating an increase in tissue conductivity as would normally be observed with a comparable liquid solution. A more efficient cell permeabilisation would result in better results where electroporation is being delivered alone or as a tool to aid in the uptake of molecules into the cell.