A nanofilter is a state-of-the-art filter with microscopic pores.

Some nanofilters, like the ones used by Grifols, have proven to be effective at removing viruses from protein solutions. Nanofiltration can remove both enveloped and non-enveloped viruses. Extent of removal is linked to the pore size of the nanofilter and the size of viruses.

Nanofiltration down to 20 nm is included as a specific viral elimination step in the production of Flebogamma^® 5% DIF, an immune globulin solution (IGIV).

Nanofiltration ( ≥70 kDa) is used in the production of AlphaNine^® SD , a coagulation product.