SECTION TWO 



ACRIDINE ORANGE-MASSON TRICHROME STAIN 

 A selective fluorescence stain for mucin 



G. Acridine orange, o*i% in distilled 

 water 



Technique: 



1. Fix pieces of tissue in Bouin's fluid for three days, or in 

 Regaud's fluid for one day. 



2. Embed in paraffin wax as usual and cut sections at 5 /z. 



3. Attach sections to slides and take down to distilled water in 

 the usual manner. 



4. Mordant in the iron alum (solution A) for five minutes at 

 45°Cto5o°C. 



5. Wash well in several changes of distilled water. 



6. Stain for five minutes in Regaud's haematoxylin (solution 

 B), for five minutes at 45° C to 50° C. 



7. Rinse in distilled water. 



8. Differentiate in picric alcohol (solution C), controlling by 

 examination under the microscope, while the preparation is still 

 wet. 



9. Wash in running tap water for a minute or so. 



10. Stain for five minutes in ponceau fuchsin (solution D). 



11. Rinse in distilled water. 



12. Differentiate in the phosphomolybdic acid (solution E) for 

 five minutes. 



105 



