Biotechnology Letters 22: 1407–1411, 2000. © 2000 Kluwer Academic Publishers. Printed in the Netherlands. 1407 Preparation and characterisation of Cibacron Blue F3G-A poly(ethylene) hollow-fibre affinity membranes F.J. Wolman 1 , M. Grasselli 2 , E.E. Smolko 3 & O. Cascone 4,∗ 1 C´ atedra de Microbiolog´ ıa Industrial y Biotecnolog´ ıa, Facultad de Farmacia y Bioqu´ ımica, Universidad de Buenos Aires, Jun´ ın 956, 1113 Buenos Aires, Argentina 2 Departamento de Ciencia y Tecnolog´ ıa. Universidad Nacional de Quilmes, Roque S´ aenz Peña 180, (1876) Bernal, Prov. Buenos Aires, Argentina 3 Centro At´ omico Ezeiza, Ezeiza, Argentina 4 Campichuelo 103 - 2 ◦ A, 1405 Buenos Aires, Argentina ∗ Author for correspondence (Fax: 54 11 4901 6284; E-mail: ocasco@huemul.ffyb.uba.ar) Received 17 April 2000; Revisions requested 12 May 2000; Revisions received 5 July 2000; Accepted 6 July 2000 Key words: affinity chromatography, Cibacron Blue F3G-A, hollow-fibre membranes, protein purification Abstract Poly(ethylene) hollow-fibre membranes with immobilised Cibacron Blue F3G-A were obtained in four different ways from epoxy-activated fibres. Membranes with a maximum capacity of 26 mg lysozyme ml −1 and a dye den- sity of 52 μmol ml −1 were obtained when ammonia was used to open the epoxy group before dye immobilisation. Pure water flux of the modified membranes at 1 bar pressure was 1.0 cm min −1 , thus meaning only a reduction of 1.5-fold with regard to the unmodified membranes. The support-dye bond was stable as judged by the unmodified capacity of the membranes and the negligible amount of dye leaked after 520 h of exposure to 6 M urea in 0.5 M NaOH. Introduction Triazinic dyes have been extensively utilised to ob- tain pseudo-biospecific ligand affinity chromatogra- phy matrices due to their low cost, availability, sim- ple immobilisation reaction, biological and chemical degradation resistance as well as acceptable selectiv- ity and capacity. Cibacron Blue F3G-A has been the most utilised triazinic dye for purification of differ- ent proteins (Lowe & Pearson 1984). As with many affinity chromatographic ligands, triazine dyes have been immobilised to a wide variety of support matrices in the search for an ideal system. Some of the sup- ports examined in this way include agarose, dextrans, polyacrylamide, agarose-polyacrylamide copolymers, cellulose and glass. Among them, soft-gels have been extensively used as support matrices for triazinic dyes (Angal & Dean 1977, Camperi et al. 1996). The microfiltration dye-affinity membrane is a good alternative to macroporous dye-affinity beads as proteins are directly transported by convection to the affinity group onto the inner surface of the mi- crofiltration membrane, thus making adsorption rates faster. Additionally, membrane chromatography can overcome the high operating pressure characteristic of bead-based chromatography (Brandt et al. 1988, Thömmes & Kula 1995, Gebauer et al. 1997). More- over, solutions containing debris or solid particles can be processed directly in the cross-flow mode (Roper & Lightfoot 1995, Grasselli et al. 1999). Cibacron Blue F3G-A has been coupled to nylon flat-sheet membranes via various spacers (Cham- pluvier & Kula 1990, Weissenborn et al. 1997), flat-sheet cellulose membranes (Liu & Fried 1994), poly(ethyleneimine)-coated titanium membranes (Li & Spencer 1994), microporous poly(2-hydroxyethyl methacrylate) membranes (Denizli et al. 1997), poly(vinyl alcohol)-coated poly(propylene) hollow- fibre membranes (Schisla et al. 1995), or macroporous flat-sheet chitosan and chitin membranes (Ruckenstein