Photorelease on One Side of Cell (IMAGE) University of Washington Caption Photorelease of epidermal growth factor (EGF) proteins on one side of a human cell. Left: EGF (green) is tethered to a hydrogel a single human cell (center). The cell membrane binds EGF, making its membrane green. Middle: The hydrogel after using a laser to untether and release EGF proteins on the top portion of the cell. Right: An image showing the difference in green fluorescent color between post- and pre-release images. Note the increase in color in the top portion of the cell, which indicates that the cell has started to internalize the untethered EGF proteins but only on one side. Scale bar is 10 micrometers. Credit Shadish, Benuska and DeForest, 2019, <em>Nature Materials</em> Usage Restrictions Must include credit 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.