Phosphatidylethanol (PEth) is formed primarily by transphosphatidylation of phosphatidylcholine (PC) by phospholipase D. Most PEth (about 75%) is incorporated into erythrocyte membranes, and is one of the longest-lived circulating EtOH metabolite yet identified. BODIPY-FL Phosphatidylethanol (BODIPY-FL PEth) is a novel flourescent phospholipid analog of this intriguing and rare lipid found in nature.