Liver Stained for Fat with Oil Red O (IMAGE) University of Pennsylvania School of Medicine Caption A liver was stained for fat with Oil Red O. The sample on the left is from a mouse whose liver is depleted of histone deacetylase 3 (HDAC3) and is strongly stained red, indicating that it is full of fat. The sample on the right is from a mouse in which "enzyme-dead" HDAC3 is preventing the fatty liver. Note that there is much less red staining, even though the HDAC3 does not possess the enzyme activity for which it is named. Credit Zheng Sun, Ph.D., Mitchell A. Lazar, M.D., Ph.D., Perelman School of Medicine, University of Pennsylvania 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.