STAINING, PRACTICAL AND THEORETICAL 



SCHIFF'S REAGENT (Feulgen reaction) 

 For deoxyribonucleic acid 



Solutions required: 



A. Schijf's reagent"^ 



Distilled water . . . . . . lOO ml. 



Basic fuchsin (Michrome No. 412) 0-5 gm. 



Boil the water ; then allow it to cool to about 70° C. be- 

 fore adding the dye and dissolving by stirring. Allow the 

 solution to cool to about 25° C, then add: 

 Potassium metabisulphite . . i gm. 

 HClN/i 10 ml. 



Plug the neck of the flask with cotton wool ; allow to 

 stand several hours or overnight; then add: 

 Decolorizing charcoal . . i gm. 



Shake well, then allow to stand for about half an hour 

 before filtering. 



Note: The finished solution should be colourless, and 

 if kept in a well-closed bottle, free from dust and other 

 extraneous matter, it will keep for many weeks or several 

 months, even in a clear glass bottle exposed to daylight. 



B. Potassium metabisulphite . . 0*5 gm. 

 HCl, cone. . . . . . . 5 ml. 



Distilled water . . . . . . 100 ml. 



C. Fast green FCF, 0-5% aqueous 



Technique: 



1. Sections of Zenker-fixed material are taken to water in the 

 usual manner. 



2. Treat for the removal of mercuric deposit by the standard 

 technique. 



3. Rinse in distilled water. 



4. Rinse briefly in N/i HCl. 



5. Immerse in N/i HCl for five minutes at 60° C. 



* Note: This is sometimes referred to as Feulgen's Fuchsin. 



400 



