Whatman 10401312 Cellulose Nitrate Membrane Circle, plain, 0.2 um pore size, 47 mm, 100 per pack. Regular Price: $171.84. Price $149.42. Add To Cart. Whatman 10408712, Mixed Cellulose Ester Filter, ME Range (ME 24), 3.1 mm white/black grid for membrane-butler, 0.2um pore size, 47 mm circle (400 pcs) Regular Price: $471.78.