CellMicroSieves (TM) filters manufactured by BioDesign Inc of New York allow the separation of multiple cell types using a filter that will not bind cells or proteins. Eleven pore sizes are available in sheets (3 sheets of 12 by 12 inches per package), rolls (2 feet by 3 feet), and 47mm circles (10 per package) that are extremely useful for specific cell type separation, stem cell isolation, hybridoma production, collection of cells from media, and many other uses where a strong non-binding specific sized pore filter is needed. Can be repeatedly steam sterilized retaining its pore size. A pure nylon thread product with no extractable materials that is specifially made for biologial research.