SECTION FOUR 



Dissolve the potassium iodide in the water, then add 

 the iodine and shake till dissolved, afterwards adding 

 the alcohol and mixing well. 



B. Crystal violet i% aqueous. 



C. Picric acid 0*5% in absolute alcohol. 



Technique : 



1. Fix in Navashin or Fleming. 



2. Take the preparation (smear or section) through to 70% 

 alcohol in the usual way. 



3. Pass through 95% alcohol. 



4. Mordant for fifteen minutes in solution A. 



5. Rinse well in water. 



6. Stain with solution B for ten to fifteen minutes. 



7. Rinse well in water. 



8. Immerse again in solution A for a few minutes. 



9. Rinse in 95% alcohol. 



10. Immerse the preparation for about one second in the picric 

 acid solution. 



11. Wash immediately with absolute alcohol for a few seconds. 



12. Rinse in clove oil until the violet stain ceases to come out of 

 the preparation. 



13. Wash well in two changes of xylol. 



14. Immerse in a jar of xylol for about an hour. 



15. Drain off excess xylol and mount in Canada balsam in xylol 

 or in Cristalite. 



Results: 



Chromosomes: rich purple, each chromosome being sharply 

 defined, Cytoplasm: yellow. 



Note: This technique is an improvement on Newton's Gentian 

 Violet - Iodine in that fading does not occur and sharp differentia- 

 tion is obtained of Chromosomes that are close together. 



Reference: Smith, F. H. (1934), Stain Tech., 9 95-6. 



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