A NEW HISTOCHEMICAL METHOD FOR DETECTION OF SIALIC ACIDS USING A PHYSICAL DEVELOPMENT PROCEDURE

We have established an efficient histochemical method for demonstratio n of sialic acids in light microscopy. The method consists of a select ive periodate oxidation-phenylhydrazine blockade and a thiocarbohydraz ide-silver protein sequence followed by a physical development procedu re. From the results obtained by the present experimental and control studies in tissue sections from a series of rat and mouse organs, such as stomach, duodenum, colon, liver, sublingual gland, lung, and kidne y, the specificity and sensitivity of the method were sufficient. In t he tissues tested, sialic acids were visualized as distinct brownish a nd blackish reaction products. Comparisons of the new method with the periodic acid-phenylhydrazine-Schiff (PA-P-S) or selective periodate o xidation-Schiff (PA(+)-S) method employed hitherto have confirmed that the new method reported here is higher in efficiency and visibility o f reaction products than the latter two methods.