Effect of Flux Decay on Virus Retention

This application note describes virus retention properties of Virosart® CPV, the Sartorius 20 nm Polyethersulfone membrane virus filter, and outlines its virus retention data with increasing flux decay profiles for several different proteins. 20 nm retentive virus removal filters are a well established, robust method for clearing both large and small viruses within a purification process. In order to validate the efficiency of these filters, a virus spiking trial must be performed. It has been shown that the virus reduction capability of some virus removal filters decreases with increasing flux decay. This decrease in log reduction value is dependent on several factors including protein concentration, product purity and plugging mechanism (adsorptive vs. pore plugging). The influence of these parameters on the overall flow decay profile of each virus filter has to be examined case by case.