Demonstration of protease isoenzymes by two-dimensional polyacrylamide electrophoresis

A two-dimensional polyacrylamide electrophoresis system is described for the detection of protease isoenzymes using 4-methoxy-2-naphthylamine derivates as substrates. With this technique is possible to detect isoenzymes differing in molecular weight by separation according to size and shape. This is not possible by the use of isoelectric focusing alone.