The purification and characterization of an antihemorrhagic factor in woodrat (Neotoma micropus) serum.

A protein antihemorrhagic factor was purified from the serum of the southern plains woodrat (Neotoma micropus) by gel filtration and ion exchange chromatography. The homogeneity of the purified factor was measured by disc electrophoresis in polyacrylamide gel. The factor had an isoelectric pH of 4.1, a molecular weight of 54,000, and migrated with alpha-globulins in disc electrophoresis. The factor failed to form a precipitate with crude western diamondback rattlesnake (Crotalus atrox) venom and did not show proteolytic activity with gelatin or hide powder, N. Micropus has an antihemorrhagic factor in the serum which appears similar to that found in hispid cotton rat (Sigmodon hispidus) and in opossum (Didelphis virginiana) sera.