Biomolecules can be retrieved in two different membrane filtration methods. The standard method utilized the chemical interaction between the molecule and the membrane polymer. With increased interaction, the membrane is able to adsorb more proteins on its pore surface. In this process, the adsorption sensitivity can be increased by smaller pore sizes, as the surface increases. This is especially important for low amounts and small molecules. The pores of the membrane in this method has to be larger than the molecules, since they have adsorb the pore wall. Once the capacity is reached, the molecules don’t bind to the polymer no more and additional molecules are lost. In a final step, the molecules are resolved in a specific solvent, e.g. DMSO. For this application, we offer our PVDF membranes, as they have very good protein binding capacities.
The second process is a simple physical filtration. In such a separation process the molecule will be in a simple filter cake on top of the membrane. The filter cake can consequently be easily resuspended and directly reused. The main drawback of this recovery method is the unselectivity, every molecule that is larger than the pore, will be in the filter cake. On the other hand, with this method, it is nearly irrelevant what the chemical properties of the target molecule is, as the recovery is solely based on the molecule size. For this application, we propose our PEEK membranes, as they have little chemical interactions which could lead to unwanted adsorption.