PTFE Membrane Filters, 0.22 um, 47mm, Nonsterile, 100 per pack, SF13856. Regular Price $92.06 Price $80.05. Add to Cart. Add to Wish List. Tisch Scientific MCE Membrane Filters, White w/Black Grid, 0.22 µm, 50 mm, Nonsterile, 100 Pack, SF14718. Regular Price $38.97 Price $33.89.