Blood Polyhedrocytes (image) University of Pennsylvania School of Medicine Share Print E-Mail Caption A previously unknown shape for red blood cells in contracted clots. The red blood cells can be compressed into many-sided, closely-packed polyhedral structures instead of their free-flowing bi-concave, disc shape. Credit John Weisel, PhD, Perelman School of Medicine; Blood, Prepublished online December 13, 2013; doi:10.1182/blood-2013-08-523860 Usage Restrictions Please try to use full image credit. Share Print E-Mail 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.