The British Society for Haematology Guidelines on the use and monitoring of heparin 1992: second revision. BCSH Haemostasis and Thrombosis Task Force.

Properties of unfractionated and low molecular weight heparin CHEMISTRY OF HEPARIN Unfractionated heparin is a naturally occur- ring glycosaminoglycan produced by the mast cells of most species. It is extracted from porcine or bovine mucosa, all the products currently used in the United Kingdom being of porcine origin. It consists of alternating chains of uronic acid and glucosamine, sul- phated to varying degrees, and has a molecu- lar weight range of 5000-35 000, with a mean of about 12 000-14 000.