[ To replace table on p. 16S of the Microscope and Microscopical Methods, 6th ed., 

 by S. H. Gage. Comstock Pub. Co., Ithaca, N. K] 



ORDER OF PROCEDURE IN MAKING MICROSCOPICAL PREPARATIONS BY 

 THE PARAFFIN METHOD. > 



§ 284. It will be seen from this table and from sections 268 to 283 

 that it requires from 5 to 7 days to get a microscopical preparation by 

 the paraffin method if one starts with the fresh tissue. Depending on 

 the method of fixing and hardening, the time may be much greater. 

 Unless much time is lost in waiting one must plan ahead in histological 

 work. 



Fixing and hardening the tissue or 



organ ($ 269), 4 days or more. 

 Dehydrating the object to be cut in 



95/3 or stronger alcohol (J 270), 1 



to 24 hours. 

 Displacing the alcohol and clearing 



tissues with cedar- wood oil. (See 



\ 271a, below). 2 to 24 hours. 

 Infiltrating the tissue with parafiin 



in the paraffin oven {\ 272, \ 271a), 



2 to 24 hours. 

 Imbedding in paraffin {\ 273), 10 



minutes. 

 Cutting the sections (<S 274), 10 min- 

 utes. 

 Extending the sections with warm 



water. (See \ 274a, below. ) 

 Fastening the sections to a slide 



(| 274a, 275), 5 minutes to 24 



hours. 

 Removing the paraffin (? 276), 10 



minutes to 24 hours. 

 Washing in 95% alcohol to remove 



the benzin(§ 277), 2 minutes. 



n. Washing with water, note, p. Aa-Z 



12. Staining with an aqueous dye ( § 278- 



279), 2 minutes to 24 hours. 



13. Washing away the superfluous stain. 



with water (§. 278-279). 



14. Staining with a general dye (1264a, 



280a), 10 seconds to 10 minutes. 



15. Washing the sections with water 



(? 280). 



Dehydrating the stained sections in 

 95% alcohol (? 281), 3 minutes to 

 24 hours. 



Clearing the sections (\ 282), 2 min- 

 utes to 24 hours. 



Mounting in balsam (§ 283), 1 to 5 

 minutes. 



19. Sealing the cover-glass (<j 238), 2 



minutes. 



20. Labeling the preparation (? 291), 2 



minutes. 



21. Cataloging the preparation (? 294), 



5 to 10 minutes. 



16 



17 



18. 



