Heparin (from Ancient Greek ηπαρ (hepar), liver), also known as unfractionated heparin, a highly-sulfated glycosaminoglycan, is widely used as an injectableanticoagulant, and has the highest negative charge density of any known biological molecule.^[1] It can also be used to form an inner anticoagulant surface on various experimental and medical devices such as test tubes and renal dialysis machines.