Particles and activated T-Cells (IMAGE) Yale University Caption Stimulatory particles (red) bound to activated T-cells (blue) as seen by fluorescence microscopy. Scale bar = 10 µm. Credit Steenblock-Fahmy/Yale 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.