Direct capture of plasma factor VIII:C by ion exchange chromatography.

An ion exchange medium, DEAE-Fractogel 650M, can be used to capture factor VIII (FVIII) directly from plasma. Previous reports have focussed on the use of this medium to capture FVIII from cryoprecipitate. In this report, citrate phosphate dextrose plasma was batch-stirred with DEAE-Sephadex A50, filtered, diluted, loaded onto a column packed with DEAE-Fractogel TSK 650M, and chromatographed. Most of the unwanted proteins flowed through the gel unadsorbed. Bound FVIII was eluted by increasing the ionic strength of the buffer. A citrate-based buffer gave an overall FVIII:C yield of 670 IU/kg plasma with a specific activity of 0.68 IU FVIII:C/mg protein. This process gave a higher yield of FVIII:C but significantly more prothrombin complex factors than cryoprecipitation. This method is a promising alternative to cryoprecipitation of FVIII.