Identification of cytochemical reaction products by scanning x-ray emission microanalysis

The primary, secondary, and final reaction products of the cytochemical staining method for alkaline phosphatase have been demonstrated by x-ray emission microanalysis. The advantages and limitations of the technique in measuring reaction products are discussed. Scanning x-ray emission analysis provides a rapid way of detecting and measuring the amounts of individual elements in cytochemical reaction products. It has a resolution of 1 micro and a sensitivity of 0.01 per cent (w/v). It will provide information on the elementary composition of the products in situ and will permit study of the efficiency of conversion of one product to another. It will also yield information on the diffusion of reaction products in the tissue.