Isoelectric focusing of human tissue alkaline phosphatase isoenzymes in agarose gel.

Human tissue alkaline phosphatases obtained by butanol treatment of tissue homogenates were subjected to isoelectric focusing in agarose gel. Inactivation of alkaline phosphatases by ampholytes was prevented by incorporating zinc into the gel prior to electrofocusing and to the authors' knowledge this has not been reported before. The addition of zinc did not alter the pH gradient and the method was reproducible. Ampholytes from two different manufacturers differed in their requirements for zinc in preventing inhibition of alkaline phosphatase. The method is more rapid than previously described methods and is very sensitive.