MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



Sodium acetate M/5 . . • • 5 ml. 

 Absolute alcohol . . . . 35 ml. 



Note: This solution, which deteriorates after a 

 few days, should be kept in an amber bottle. 



C. Reducing rinse: 



Potassium iodide . . . . i gm. 



Sodium thiosulphate . . . . i gm. 



Distilled water . . . . . . 20 ml. 



Dissolve ; then add with stirring : 

 Absolute alcohol . . . . 30 ml. 



Hydrochloric acid 2N . . . . 0-5 ml. 



Note: A precipitate of sulphur is slowly formed 

 and this may be allowed to settle out, or the solution 

 may be used immediately. 



The solution loses its acid reaction on keeping for 

 some time, and it should be tested with litmus paper ; 

 if the reaction is no longer acid a few drops of N/2 

 hydrochloric acid should be added until an acid 

 reaction is obtained. 



D. Feulgen's fuchsin. 



E. Sulphite wash water: 



Distilled water . . . . . . 45-5 ml. 



Hydrochloric acid, pure, cone. . . 0-5 ml. 

 Potassium metabisulphite . . 0-2 gm. 



Technique: 



Any fixative may be used but for glycogen or other easily soluble 

 polysaccharides, alcohol is the best fixative as it does not dissolve 

 such substances, and Solution B should be used in place of Solu- 

 tion A. 



1. The sections or smears are brought down to alcohol; then 

 immersed in Solution A for five minutes. 



2. Pour off solution; flood with 70% alcohol. 



3. Immerse for five minutes in Solution C. 



4. Flood with 70% alcohol; pour off; then immerse in Solu- 

 tion D for fifteen to forty-five minutes. 



5. Wash two or three times in Solution E. 



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