Purification and immunochemical characterization of human plasma factor XIII.

A detailed study of the conditions for purification of plasma factor XIII was undertaken and an optimal procedure developed. This procedure involves adsorption with aluminum hydroxide, repeated fractionation with ammonium sulfate, heat denaturation of fibrinogen, precipitation with polyethylene glycol, cryoprecipitation, and chromatography on DEAE-cellulose with gradient elution. The specific activity of the final product, as measured by the fluorescent amine incorporation assay for factor XIII, averages about 3,000-4,000 mumol dansylcadaverine incorporation/mg protein. The yield is about 20%. In SDS electrophoresis the final product has two bands under nonreducing conditions, characteristic of the a and b subunits.