More separations are also achieved with layers of polyacrylamide gels each with a different pore size. The gels can be horizontal or vertical slabs or incorporated into vertical cylinders or rods. Varying the pore size in each layer is significant especially if very small pore sizes are created. DNA of 100 base pairs (bp) or less can be separated.

Common applications of PAGE are separation of proteins and nucleic acids. Polyacrylamide gels are also used as the medium in several other types of electrophoresis described in this section.