Pores Form Only At Filter's Nanopores (IMAGE) University of California - Berkeley Caption A small voltage opens a pore in the cell membrane only at the position of a pore in the water filter, allowing molecules to flow into the cell cytoplasm without traumatizing the cell. Credit Graphic by Yuhong Cao, UC Berkeley Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.