Process for removing protein aggregates and virus from a protein solution

A process for selectively removing protein aggregates and virus particles from an aqueous solution of proteins that consists essentially of:

• first filtering a protein solution containing said protein aggregates and viruses through a device selected from the group consisting of one or more layers of adsorptive depth filters and one or more layers of charged or surface modified microporous membranes, in a normal flow filtration and constant pressure mode of operation,
• recovering the aggregate free protein solution, and secondly filtering said protein solution through one or more ultrafiltration membranes having a molecular weight cut off of between about 200 kD and about 1000 kD to retain virus particles in said one or more ultrafiltration membranes at a level of at least 3 LRV, and to recover an aqueous, virus-free protein solution.

A process for selectively removing protein aggregates and virus particles from an aqueous solution of proteins that consists essentially of:

• first filtering a protein solution containing said protein aggregates and viruses through a device selected from the group consisting of one or more layers of adsorptive depth filters and one or more layers of charged or surface modified microporous membranes, in a normal flow filtration and constant flow mode of operation,
• recovering the aggregate free protein solution, and secondly filtering said protein solution through one or more ultrafiltration membranes having a molecular weight cut off of between about 200 kD and about 1000 kD to retain virus particles in said one or more ultrafiltration membranes at a level of at least 3 LRV, and to recover an aqueous, virus-free protein solution.

A process for selectively removing protein aggregates and virus particles from an aqueous solution of proteins that consists essentially of:

• first filtering a protein solution containing said protein aggregates and viruses through a device containing one or more layers of charged or surface modified microporous membranes, in a normal flow filtration mode of operation,
• recovering the aggregate free protein solution, and secondly filtering said protein solution through one or more ultrafiltration membranes having a molecular weight cut off of between about 200 kD and about 1000 kD to retain virus particles in said one or more ultrafiltration membranes at a level of at least 3 LRV, and to recover an aqueous, virus-free protein solution.