Whatman 10401314 Cellulose Nitrate Membrane Circle, plain, 0.2 um, 50 mm, 100 per pack. Regular Price: $199.82. Price $173.76. Add To Cart. Whatman 10408714, Mixed Cellulose Ester Filter, ME Range (ME 24), 3.1 mm white/black grid for membrane-butler, 0.2um pore size, 50 mm circle (400 pcs) Regular Price