Figure 1.

Medium cut-off membranes provide clearance of large middle molecules without albumin loss. Schematic of pore size distribution in dialysis membranes. As membranes have been developed to allow the removal of large middle molecules (MMs) without albumin loss, the distribution of the pore sizes has had to be “tightened.” The pink bar represents the distribution of large MMs before albumin is lost. The solid line indicates low flux, the dotted line indicates high flux, the dot-dash line indicates high cutoff (HCO), and the large dashed line indicates medium cutoff (MCO).