title: Maintaining the ionic permeability of a cellulose ester membrane.
abstract: This paper reports the results of a series of experiments designed to test conditions that would permit NaCl to diffuse through 100 Da molecular weight cut-off (MWCO) and 1,000 Da MWCO membranes. For the 100 Da MWCO membrane, the membrane becomes completely impermeable to NaCl when dialyzed against distilled water (DW), but inclusion of one of a variety of different salts in the dialyzing solution maintains membrane permeability to NaCl. A titration experiment revealed that a minimum concentration of 0.1 mM of a salt such as KH2PO4 is required to sustain membrane permeability. In contrast, diffusion through the 1,000 Da MWCO membrane was slightly higher when DW was used as the dialysate. We conclude that the 100 Da MWCO membrane works well for a variety of dialysis applications provided that a maintenance salt is included in all dialyzing solutions.
authors.affiliation: Department of Biology, 180 Lewis Science Center, University of Central Arkansas, Conway, AR 72035-5003, USA. srunge@uca.edu
authors.forename: Steven W
authors.initials: SW
authors.lastname: Runge
authors.forename: Kyla R
authors.initials: KR
authors.lastname: Shelton
authors.forename: Shane A
authors.initials: SA
authors.lastname: Melton
authors.forename: William M
authors.initials: WM
authors.lastname: Moran
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D008567:Membranes, Artificial; D010539:Permeability / Q000187:drug effects; D012965:Sodium Chloride / Q000737:chemistry / Q000494:pharmacology
chemical_list: D007477:Ions; D008567:Membranes, Artificial; C020253:cellulose ester plastic; D012965:Sodium Chloride; D002482:Cellulose