A simple chromatographic procedure for the purification of the D dimer fragment from crosslinked fibrin.

An improved procedure for the purification of fragment D dimer derived from crosslinked plasma fibrin is described which entails chromatofocusing chromatography using PBE 94 and polybuffer 74, and gel chromatography on Sephacryl S-300. The procedure provides a preparation of D dimer which behaves as a single macromolecular entity with molecular weight 190,000 in sedimentation equilibrium studies. Only a single protein band is observed in polyacrylamide gel electrophoresis conducted in the presence or absence of sodium dodecyl sulfate, while patterns characteristic of gamma'-gamma' chains are observed under denaturing conditions after reduction of the preparation with beta-mercaptoethanol. The D dimer contains no demonstrable E antigen by a range of electrophoretic and immunologic techniques. Advantages of this method for obtaining D dimer in high yield include the use of plasma as starting material, the use of a simple lysis regimen in the presence of Ca2+, and the use of simple chromatographic techniques performed under nondenaturing conditions.