Summary
Early work on the purification of factor VIII using polyethylene glycol (PEG) indicated
that other polymers might also be used to precipitate factor VIII leaving fibrinogen
in solution. Recently polyvinylpyrrolidone (PVP) has also been advocated for this
purpose.
In this study, different concentrations and molecular weights of hydroxyethyl starch,
dextran, PEG, PVP, Ficoll, Percoll and albumin were examined for their ability to
precipitate the factor VIII complex from cooled (not frozen) fresh CPD plasma. At optimal concentrations near quantitative recovery
of VIIIR:Ag and VIII: CAg was achieved in 2 hr with minimal precipitation of fibrinogen
or total protein. The best separations were observed with hydroxyethyl starch, albumin
or Ficoll. PVP and PEG gave inferior purifications. Results for cryoprecipitate and
intermediate-purity factor VIII concentrate were inferior to those obtained with plasma.
Simple pre-concentration of plasma prior to chilling is an attractive alternative
for large scale continuous production.
Keywords
Factor VIII - Fibrinogen - Polymer - Protein precipitation
