A rapid technique for alkaline phosphatase enzyme activity in tissues.

A rapid method is described for serial determination of alkaline phosphatase enzyme activity in the rat kidney and the developing avian vertebra by using an improved paraffin embedding process and a slide staining rack. Tissue samples fixed 12 to 24 h in 80% ethanol at 0 to 4 degrees C are dehydrated in absolute acetone at 0 to 4 degrees C, and then embedded in paraffin of 50 degrees C via benzene at room temperature. The alkaline phosphatase enzyme activity is essentially demonstrated with the method of GOMORI and TAKAMATSU but modified for the use of the slide staining rack. With the new technique, the enzyme activity is completely preserved and reproducible for years in the paraffin embedded tissues. The good quality of the sections enables quantitative evaluations by video scanning.