A current trend in dialysis membrane engineering is to maximize the permeability for larger low-molecular weight proteins while retaining albumin. Protein-leaking dialysis membranes do not meet these requirements. Particularly in convective procedures, such as hemodiafiltration, their albumin leakage is too high [10]. POLYNEPHRON™, the membrane which is built in to the new Nipro ELISIO® dialyzer, is a new dialysis membrane, produced by applying an innovative spinning technique. The incentive of its development was to improve the characteristics of existing dialysis membranes, i.e., realizing a steeper sieving profile for low-molecular weight proteins without significant loss of essential larger proteins at best biocompatibility properties, for a more adequate dialysis therapy. Purpose of the planned study is to demonstrate the superior performance at lower albumin loss in different dialysis procedures of the new Nipro ELISIO® dialyzer compared with a control dialyzer with regard to the removal of the whole range of uremic toxins.