Sedimentation of plasma antihemophilic factor

Purified bovine plasma antihemophilic factor (AHF) preparations and canine plasma were sedimented in a swinging bucket type rotor of a preparative ultracentrifuge. A simple technique is described for sampling contents of the tubes for analysis after sedimentation. Sedimentation diagrams and S 20,w values are presented for AHF and fibrinogen at 4 and 21 °C. It is shown that AHF in canine plasma probably exists in an associated form, either as a polymer or associated with fibinogen. Apparently different degrees of association exist in bovine fractions, with the degree of association depending upon the ionic strength of the solution. The S 20,w value of 4.3 S probably represents the sedimentation coefficient for the AHF monomer.