MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



HEroENHAIN HAEMATOXYLIN - SAFRANIN 



A general stain for plant tissue, algae, fungi, etc., to demon- 

 strate histological and cytological structures 



Solutions required: 



A. Haematoxylin (Heidenhain) No. i. 



B. Haematoxylin (Heidenhain) No. 2. 



C. Picric acid, saturated, aqueous. 



D. Safranin 1% aqueous. 



Technique: 



1 . Fix and dehydrate tissues and embed in paraffin wax. 



Note: Algae and fungi should be treated by the Venetian tur- 

 pentine method {see page 43). 



2. Fix paraffin sections to slides ; remove wax with xylol. 



3. Pass through absolute alcohol and the usual descending 

 grades of alcohol, down to distilled water. 



4. Mordant in Heidenhain haematoxylin No. i (Solution A) 

 from one half to two hours but no longer, unless the material is 

 algae in which case as long as twelve hours may be necessary. 



5. Wash for five minutes in running tap water. 



6. Rinse well in distilled water. 



7. Stain algae for at least twenty-four hours, or other material 

 from five to seven hours, in Heidenhain haematoxylin No. 2 

 (Solution B). 



8. Wash in running water for five minutes. 



9. Differentiate in Solution C (picric acid) from twenty minutes 

 to two hours, controlling by examination at intervals under the 

 microscope. 



10. Wash for half an hour in running tap water. 



11. Rinse well in distilled water. 



12. Counterstain in the safranin solution for five to ten minutes. 



13. Rinse in distilled water. 



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