Abstract: A system for characterizing a membrane is disclosed. The system includes a container configured to dissolve a first large molecular weight marker and a second large molecular weight marker into a solution, wherein the container is connected to a reservoir. The reservoir configured to receive the solution. A filtration unit is connected to the reservoir, where the filtration unit is configured to separate the first large molecular weight marker and the second large molecular weight marker from the solution. A measuring system is configured to determine if the first large molecular weight marker is equal to or larger than a first target concentration, where if the first large molecular weight marker is equal to or larger than the first target concentration then the first large molecular weight marker it meets a first criteria for rejection by said membrane.