Application Note: Impact of the Claristep^® Filtration System on Recovery and Adsorption of Various Therapeutic Proteins at Low Sample Volumes 

We tested the novel filter device Claristep^® for the preparation of protein samples containing one of four different biotherapeutic molecules. In comparison to the standard protocols for sample preparation prior to analysis by either reversed-phase or SEC HPLC, the Claristep^® filter did not exhibit a significant difference in protein concentration if the target molecules were present with at least 1.0 g L-1. A significantly reduced product concentration was observed in the Claristep^® filtered samples compared to the standard protocol for a monoclonal antibody, if the concentrations were lower. The protein adsorption to the filter material was well described by a Langmuir adsorption isotherm. Additionally, the Claristep^® filters facilitated a rapid sample preparation with minimal volume losses.