Use of structured depth filters for virus removal

摘要

A method of reducing the titer of viruses in a solution of biologically active proteins without adversely affecting the activity of the protein, the method comprising the step of passing the solution at a pH ranging from about 5.0 to about 7.0 through a structured depth filter comprising a positively charged porous filter element, the average pore diameter of the filter element being larger than the average diameter of the viruses and the filtration being done under conditions resulting in a substantial reduction in virus titer in the filtered solution while retaining biological activity of the proteins.