Several comparative evaluation studies have been carried out to determine the relative performance of membrane adsorbers and
traditional packed-bed columns in flow-through mode, although direct comparisons can be difficult because different standards
are used to measure process capacity and flow rate.12 When such issues are taken into account, the performance of Q adsorbers is encouraging, but until now there has been no similar
evaluation of either Q or S adsorbers in retention mode.
The process outlined above demonstrates that a membrane adsorber in retention mode can be used efficiently and robustly in
a commercial antibody manufacturing process. The reproducibility analysis shows that the dual adsorber format operates successfully
to remove both positively and negatively charged impurities from the feedstream, and because of the in-series linkage between
the devices the dual system can be regarded as essentially a single, integrated polishing step. As membrane adsorbers become
more widely accepted in antibody purification, it seems that not only flow-through but also retention chromatography steps
in antibody polishing could be replaced by disposable membrane devices. Even so, the superior capacity of column chromatography
for the capture of antibodies and other recombinant proteins means that resins are unlikely to be replaced for the foreseeable
future in the primary capture step, which is the most significant bottleneck of all.13,14 .
Leonardo Giovannoni, PhD, is the head of CMC production and Marco Ventani is the head of downstream processing, both at
Philogen S.p.A., Sienna, Italy, +39 0577 588539, email@example.com
Uwe Gottschalk, PhD, is vice president of purification technologies at Sartorius Stedim Biotech GmbH, Göttingen, Germany.
Gottschalk is also a member of BioPharm International's editorial advisory board.
1. Daemmrich A, Browden ME. A rising drug industry. Chem Eng News. 2005;Jun:28–42.
2. Gottschalk U. New and unknown challenges facing biomanufacturing. BioPharm Int. 2005; 18(3):24–28.
3. Thoemmes J, Kula MR. Membrane chromatography. An integrative concept in the downstream processing of proteins. Biotechnol
4. Zhou J, Tressel T. Basic concepts in Q membrane chromatography for large-scale antibody production. Biotechnol Prog. 2006;22:341–349.