MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



SAFRANIN - TANNIC ACID - FAST GREEN 



For roots and steins 



Solutions required: 



A. Tannic acid i% in 50% alcohol. 



B. Ferric chloride 3% in 50% alcohol. 



C. Safranin 1% in 50% alcohol. 



D. Fast green FCF in clove oil to 



which has been added 7% of 

 absolute alcohol. 



Technique: 



1. Sections are fixed to slides, treated with 70% alcohol; then 

 immersed in the tannic acid solution. 



2. Immerse for about twenty seconds each in two lots of 50% 

 alcohol. 



3. Treat with the ferric chloride for about thirty to sixty 

 seconds. 



4. Wash with 50% alcohol. 



5. Stain with the safranin solution for twenty-four hours, in a 

 stoppered staining jar. 



6. Wash with 50% alcohol. 



7. Differentiate for about ten seconds in 70% alcohol. 



8. Pass through 80%, 90% and absolute alcohol, allowing ten 

 to thirty seconds in each. 



9. Stain for two or three minutes in the fast green. 



10. Pass through absolute alcohol, followed by xylol; then 

 mount in Cristalite. 



Results: 



Nuclei, red. Cytoplasm, blue-green. Lignified walls, red. 

 Cambial cell walls, black. Collenchyma walls, very dark red. 

 Parenchyma cell walls, black. 



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