  The conduction and selectivity of calcium/sodium ion channels are described
in terms of ionic Coulomb blockade, a phenomenon based on charge discreteness
and an electrostatic model of an ion channel. This novel approach provides a
unified explanation of numerous observed and modelled conductance and
selectivity phenomena, including the anomalous mole fraction effect and
discrete conduction bands. Ionic Coulomb blockade and resonant conduction are
similar to electronic Coulomb blockade and resonant tunnelling in quantum dots.
The model is equally applicable to other nanopores.
