Now You See It (IMAGE) University of South Carolina Caption An infrared camera focused on an apparently blank piece of fabric reveals blood stains, some highly diluted, after brief steaming of the surface. The pointer highlights a letter "C" drawn in 1/100-diluted blood. Credit University of South Carolina 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.