SECTION THREE 



9. Place the slides with the dry sections in the oven for a few 

 minutes until the wax melts to form a protective coating to the 

 sections. 



Note: Sections treated in this way remain unchanged for many 

 years. 



10. For use, dewax the sections with xylol. 



11. Wash well with absolute alcohol. 



12. Wash with 95% alcohol, draining and drawing off the excess 

 with a piece of filter paper. 



13. Flood slides with 0-5% celloidin. 



14. Shake off excess celloidin solution. 



15. Harden the celloidin coat by exposure to chloroform 

 vapour, or by immersion in 80% alcohol for a few minutes. 



References: 



Gomori, G. (1946). 

 Gomori, G. (1952). 



MISCELLANEOUS DEHYDRATING AND CLEARING 



REAGENTS 



ANILINE OIL 



For clearing, etc. 



This reagent, which is used in the preparation of a number of 

 staining solutions, such as aniline gentian violet, aniline fuchsin, 

 etc., will absorb a fair amount of water (more than will cajeput 

 oil) without clouding, and it is, therefore, particularly useful in 

 wet climates as a clearing agent in place of xylol. However, after 

 clearing, the aniline oil must be removed from tissues with two 

 or three changes of xylol, benzene or chloroform. It is not very 

 miscible with paraffin wax, and unless it is similarly washed out 

 of sections it will impart a brownish coloration, which will become 

 darker with age. A good quality aniline oil, which should be 

 anhydrous, will clear tissues from 95% or even 90% alcohol, 

 and sections from 70% alcohol, but it should not be used after 

 osmic acid fixation or after any fixatives containing oxidizing 

 agents such as chromium trioxide, dichromates, etc., as even 

 traces of these are liable to cause oxidation of the aniline with the 



R* 509 



