title: Purification of human immunoglobulin G by thermoseparating aqueous two-phase systems.
abstract: The purification of human immunoglobulin G (IgG) from a Chinese hamster ovary (CHO) cells supernatant was studied using an aqueous two-phase system (ATPS) composed of ethylene oxide/propylene oxide (UCON) and dextran. In UCON/dextran systems IgG partitions preferentially to the less hydrophobic dextran-rich phase (Kp<1). The addition of triethylene glycol-diglutaric acid (TEG-COOH) shifted the IgG partition into the upper phase showing significant improvements in both the recovery yields and purity. The purification of IgG from a CHO cell supernatant with UCON 2000/dextran/TEG-COOH system was optimised using a central composite design. Using an ATPS composed of 8% UCON, 6% dextran and 20% TEG-COOH, IgG was purified, in two steps, with a global yield of 85% and 88% purity. Statistical valid models were obtained to predict the effect of the experimental conditions on the IgG yield and purity, for both extraction and back-extraction steps. A system composed of 10% UCON, 5.5% dextran and 20% TEG-COOH was identified as the best compromise between final purity and yield.
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Avenida Rovisco Pais, 1049-001 Lisbon, Portugal.
authors.forename: I Filipa
authors.initials: IF
authors.lastname: Ferreira
authors.forename: Ana M
authors.initials: AM
authors.lastname: Azevedo
authors.forename: Paula A J
authors.initials: PA
authors.lastname: Rosa
authors.forename: M Raquel
authors.initials: MR
authors.lastname: Aires-Barros
mesh_terms: D000818:Animals; D016466:CHO Cells; D005591:Chemical Fractionation / Q000379:methods*; D006224:Cricetinae; D003412:Cricetulus; D003911:Dextrans / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D005027:Ethylene Oxide / Q000737:chemistry; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry / Q000302:isolation & purification*; D013696:Temperature
chemical_list: D003911:Dextrans; D004852:Epoxy Compounds; D007074:Immunoglobulin G; D005027:Ethylene Oxide; C009068:propylene oxide