Ranil Wickramasinghe, Colorado State University, Department of Chemical Engineering, Fort Collins, CO 80523-1370, Jonathan O Carlson, Microbiology, Immunology and Pathology, Colorado State University, Department of Chemical Engineering, Fort Collins, CO 80523-1370, Christopher Teske, Institut für Biotechnologie II, Forschungszentrum Jülich,, Jülich, Germany, Joergen Hubbuch, Institut für Biotechnologie II, Forschungszentrum Jülich, Jülich, Germany, and Mathias Ulbricht, Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Essen, Germany.
Purification of virus particles for viral vaccines and applications of gene therapy is a major large scale separations challenge. Here adsorption of Aedes aegypti densonucleosis virus by anion and cation exchange membranes has been investigated. As the virus particles are viable at pH values above and below their isoelectric point, adsorption by anion and cation exchange membranes is feasible.
The capacity of the membranes for virus particles is orders of magnitude less than the manufacturer's stated capacity for model proteins such as BSA and lysozyme indicating that binding patterns are very different for different sized solutes. In order to visualize solute binding confocal laser scanning microscopy (CLSM) has been used to observe binding of thyroglobulin, BSA and lysozyme to cation exchange membranes. The results are in qualitative agreement with the measured capacities for virus particles, BSA and lysozyme. However, the results also indicate that the binding patterns for thyroglobulin, BSA and lysozyme are very different. CLSM could be a useful visualization technique when designing membranes with optimized pore structures.