RBC Membrane Fluctuation (image) University of Illinois at Urbana-Champaign Caption This is a map of membrane fluctuations in a normal red blood cell, on average up to 50 nanometers. Measuring these fluctuations over time, Illinois researchers found that the membranes stiffen as they age, which impedes the cell's function. Credit Gabriel Popescu Usage Restrictions None 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.