Patent ID: 8796430

Claim:
A method for preparing an enriched IgG composition from plasma, the method comprising the steps of: (a) precipitating a cryo-poor plasma fraction, in a first precipitation step, with between about 6% and about 10% alcohol at a pH of between about 7.0 and about 7.5 to obtain a first precipitate and a first supernatant; (b) precipitating IgG from the first supernatant, in a second precipitation step, with between about 20% and about 25% alcohol at a pH of between about 6.7 and about 7.3 to form a second precipitate; (c) re-suspending the second precipitate to form a suspension; (d) precipitating IgG from the suspension formed in step (c), in a third precipitation step, with between about 22% and about 28% alcohol at a pH of between about 6.7 and about 7.3 to form a third precipitate; (e) re-suspending the third precipitate to form a suspension; and (f) separating the soluble fraction from the suspension formed in step (e), thereby forming an enriched IgG composition, wherein at least one of the first precipitation step, second precipitation step, or third precipitation step comprises spray addition of the alcohol, the spray addition in the form of fine droplets or mist of the alcohol.