title: Treatment of dialysis membranes for simultaneous dialysis and concentration.
abstract: Dialysis membranes used for simultaneous dialysis-concentration required pretreatment to remove uv-absorbing compounds leached from the membranes and to reduce the absorption of protein to the membranes. This was accomplished with sodium carbonate and ethanol or with "sulfur-removal solutions." Protein determinations were made with a micro-Bradford protein reaction and with uv absorbance at 280 nm. Soluble membrane components contributed to aberrant uv spectra and altered the ratio of 280/260-nm absorbance. Simultaneous dialysis and concentration in the micro protein dialyzer-concentrator apparatus, combining aspects of thin-layer dialysis and ultrafiltration, resulted in rapid removal of salts from the protein solutions. Prior treatment of membranes reduced uncertainties in retentate recoveries, eliminated uv-absorbing components of membranes, and improved recoveries of protein.
mesh_terms: D000085:Acetates; D001386:Azides; D002254:Carbonates; D003956:Dialysis; D000431:Ethanol; D008567:Membranes, Artificial; D011506:Proteins / Q000302:isolation & purification*; D012710:Serum Albumin, Bovine / Q000302:isolation & purification; D019810:Sodium Azide; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000085:Acetates; D001386:Azides; D002254:Carbonates; D008567:Membranes, Artificial; D011506:Proteins; D012710:Serum Albumin, Bovine; D000431:Ethanol; C005686:sodium carbonate; D019810:Sodium Azide; C018824:ammonium acetate