Abstract: A system for investigating a membrane including a sealing chamber containing a liquid container is described. The liquid container is configured to hold a liquid medium in open communication with a controlled atmosphere inside the sealing chamber. A flow cell is disposed outside the sealing chamber and includes flow channels separated by the tissue. A set of liquid ducts is connected to one of the flow channels and configured to carry the liquid medium from the liquid container, through a barrier of the sealing chamber to an entrance of the flow channel into the flow cell, and carry at least part of the liquid medium exiting the flow channel from the flow cell back into the liquid container.