Cardiolipin (CL) is a unique phospholipid with a very interesting chemical and specific ultrastructural characteristics. It is a highly acid dimer of phosphatidylglycerol (PG) and phosphatidic acid (PA), containing four acyl chains; three glycerols and two phosphate headgroups. Due to deprotonation of one of one of these phosphate groups, cardiolipin is negatively charged in physiological pH. https://www.cd-bioparticles.net/p/10387/cl-liposomes