Cell and gene therapy, new vaccines and the production of monoclonal antibodies are the most dynamic areas in the biopharmaceutical industry. Their use in research and development, in diagnostics and therapeutic treatments has required complex, multi-stage purification processes to date, using separation columns that are costly and slow.
Chromatographic membranes have increasingly gained ground as an alternative to separation columns. This is because they achieve higher flow rates and an effective transfer of mass. Biomolecules, which are adsorbed through their positively or negatively charged binding sites, can however only be recovered by means of larger changes in pH values or through high salt concentrations in the rinsing fluid, which may compromise delicate biomulecules or be difficult to control in order to maximize yield and prevent ‘bleed’ or mixing of the product of importance with other substances.
Analytical systems such as HPLC also benefit from separation techniques that provide instruments with purified samples.
The cleaner, faster, cost reducing alternative: digital membrane chromatography. By applying a thin gold layer on both sides of a membrane, and when connected to an electricity source, the chemical binding capacities of the stationary phase can be switched. Both adsorption and desorption occur through simple potential regulation. The process can be repeated as often as is necessary. This makes the massive use of buffer solutions or increases in salt concentration for antibody purification, as well as an increase in the concentration of endotoxins, obsolete. Membrane chromatography goes digital.