Aluminum phosphate visualisation of acid phosphatase activity: a biochemical and x-ray microanalysis study

A new method is described that demonstrates acid phosphatase activity in the cells of the proximal tubules of the rat kidney. The method is based on the formation of an insoluble aluminum phosphate precipitate. Microanalysis was used to demonstrate the presence of intracellular aluminum and determine the quantity present under the probe. Parallel biochemical studies showed that the aluminum precipitate was indeed due to acid phosphatase activity.