46 Microscopic Histochemistry 



a) Method of Komaya^^ 



Make up two solutions: solution A, 0.5 g. of quinine sulfate 

 or hydrochloride in 25 ml. of 2-3 per cent H2SO4; solution B, 

 a 5 per cent solution of potassium iodide. For use, mix equal 

 parts of solutions A and B and pour the mixture over the 

 slide. After 5-10 minutes, decant the reagent, counterstain 

 with a dilute (about 0.05 per cent) solution of light green 

 to which a few drops of the reagent are added. Blot section, 

 dehydrate, and mount it in balsam. Bismuth orange-red. 



h ) Method of Castel^^ 



Same as that of Komaya, except that quinine is replaced 

 by brucine. Results practically the same with both methods. 



2. Treat section with a dilute solution of bromine (dis- 

 solve a few crystals each of KBr and of KBrOs in a Coplin 

 jarful of distilled water and add a few drops of concentrated 

 HCl). Granules of gold and bismuth are completely dis- 

 solved in 10-15 minutes; silver is bleached (formation of 

 bromide). Wash the slide; pour over it any photographic 

 developer; silver bromide will be reduced to black metallic 

 silver. 



B. NONMETALLIC ELEMENTS 



Chlorine.— The chloride ion can be localized in frozen- 

 dried material only.^^ The reagent is a dilute solution of 

 AgNOs (0.1-2 per cent; concentration not important), pref- 

 erably in 70-95 per cent alcohol. C1~,C03", and HPO^^will 

 all be precipitated by it; however, dilute ( about 0.5 per cent ) 

 nitric acid will remove phosphate and carbonate, and only 

 chloride will remain undissolved. This can then be reduced 

 to metallic silver, either by exposure to direct sunlight or by 

 photographic developers ( see under "Calcium" ) . 



55. Komaya, G.: Arch. f. Dermat. u. Syph., 149:277, 1925. 



56. Castel, P.: Bull, d'histol. appliq. a la physiol., 13:290, 1936. 



57. Gersh, I.: Proc. Soc. Exper. Biol. & Med., 38:70, 1938. 



