Testing and characterizing the simple pore

1. 1. We define a simple (or singly-occupied) pore and show that any pore which is fully occupied by a single substrate particle behaves as a simple pore at the level of steady-state analysis. 2. 2. The analysis is independent of assumptions as to (a) symmetry, (b) equilibrium, (c) the distribution of electrical potential in the membrane, and (d) the presence or absence of unstirred layers. 3. 3. We suggest simple experimental procedures involving only one substrate, the results of which can be used to test for and characterize the simple pore. For ions, only electrical measurements are needed.