Filtering Blood (IMAGE) Massachusetts Institute of Technology Caption Pictured on the left is a spleen; on the right are red blood cells. ""We have presented results showing that the spleen is the main organ that defines the shape of the circulating red blood cells" says Ming Dao, a principal research scientist in MIT's Department of Materials Science and Engineering. Credit MIT News Usage Restrictions Images for download are made available to non-commercial entities, press and the general public under a Creative Commons Attribution Non-Commercial No Derivatives license. You may not alter the images provided, other than to crop them to size. A credit line must be used when reproducing images. 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.