Dr. Marrero gave an introduction about the basic concepts of membrane physiology and how different ions moves across the plasma membrane. In the 3 hours introduction, he covered topics such as differential ion distribution, membrane potential, among other topics, as well as different strategies used to monitor voltage and currents through specific ion channels. In the 4-5 hours practical session, the participants learned how to prepare glass electrodes for microinjection, how inject oocytes with RNA and how to perform Two-Electrode Voltage Clamp (TEVC) and monitor specific currents in oocytes. Dr. Marrero and Lizardi supervised the performance of all the participants and ensure that all of them experienced all the three basic steps of this electrophysiology technique.