GB883549A - Improvements in and relating to the purification of antihaemophilic globulin - Google Patents

Abstract

A process for the preparation of a fibrinogen-reduced antihaemophilic globulin (A.H.G.) solution comprises treating an aqueous buffered solution of mammalian blood plasma or a crude concentrate containing A.H.G. derived therefrom at a pH of 6 to 8 with an ion exchanger whereby only a proportion of the total available protein, controllable by adjustment of the ionic strength of the solution, is adsorbed, but that this adsorption is selective for the A.H.G. component, followed by washing the ion exchanger free from unadsorbed material with an aqueous buffer solution at the same pH and of the same ionic strength or slightly less than that employed for adsorption then followed by eluting with an aqueous salt or buffer solution at a greatly increased ionic strength to that of the original aqueous buffer solution and within the pH range 6-8 to produce the purified A.H.G. solution in which the A.H.G. is associated with less fibrinogen than was the original solution. Specified ion exchangers are carboxylic ion exchange resins derived from methacrylic acid and cross-linked with divinyl benzene, basic ion exchange resins derived from cross-linked polystyrene carrying quaternary ammonium groups and cellulose derivatives carrying diethylaminoethyl groups. Aqueous phosphate buffers e.g. sodium phosphate and citrate-phosphate buffers are used as buffers. For acidic exchangers when adsorbing, the buffer should be at a molarity of 0.2-0.3 M and for basic exchangers at a molarity of 0.15-0.5 M. Elution from an acidic exchanger is facilitated by increasing the pH and from a basic exchanger by lowering the pH. The eluting phosphate buffer solution should be of a molarity of 0.6-0.7 M or alternatively a 4-6% solution of sodium chloride buffered with phosphate pH 7, molarity 0.1 M, may be used.