182 



COLLODION SECTIONING 



[CH. VII 



Fig. 152. Perforated sectio m lifter. This is easily made by soldering a wire 

 to some very thin sheet brass or copper, and then perforating this with a coarse 

 needle or fine awl. Any roughness must be removed by using a fine oil stone. 



ORDER OF PROCEDURE IN MAKING MICROSCOPICAL PREPARATIONS BY THE 



COLLODION METHOD 

 \ 280. It will be seen from this table, and sections 267-281, that it requires 

 about five days to get a microscopical preparation if one commences with the 

 fresh tissue. Other methods of hardening might require as many months. It is 

 evident, therefore, that one must exercise foresight in histology or much time 

 will be wasted. 



1. Fixing and hardening the tissues 12. Removing the oil from the sections 



(§ 267), 4 days or more. 



2. Dehydrating the object to be cut in 

 95% or stronger alcohol (§ 268), 2- 

 24 hours. 



3. Saturating the tissue in ether-alcohol 

 (§ 269), 2-24 hours. 



4. Infiltrating with thin collodion 

 ($ 270), 2 hours to 2 days. 



5. Infiltrating in thick collodion ( § 27 1 ) , 

 5 hours to several days. 



6. Imbedding the tissue (§272), 15 to 

 20 minutes. 



7. Hardening the collodion with chlo- 

 roform {I 273), 5-24 hours. 



8. Clarifying and further hardening the 

 collodion with castor-xylene (§ 273), 

 10-36 hours. 



9. Cutting the sections (§ 274), 10 min- 

 utes to 2 hours. 



10. Transferring the sections to a slide 

 with paper (§ 275), 1 minute. 



11. Fastening the sections to the slide 

 with ether-alcohol (§ 276), 1 or 2 

 minutes. 



with benzin and alcohol (§ 277), 3-5 

 minutes, or 24 hours. 



13. Staining the sections with an alco- 

 holic dye (§ 278), 2 minutes to 24 

 hours. 



14. Staining the sections with an aque- 

 ous dye (§ 279), 2-10 minutes. 



15. Removing the superfluous dye by 

 washing in water or alcohol (§ 278- 

 279), 2-5 minutes. 



16. Staining with a general dye (§ 279), 

 15-30 seconds. 



17. Washing with water or alcohol 

 (§ 278-279), 1 to 2 minutes. 



18. Dehydrating the sections in 95% al- 

 cohol (§281), 5 min. to 24 hours. 



19. Clearing the sections (§281 ), 5 min- 

 utes to 24 hours. 



20. Draining the sections, 1-2 minutes. 



21. Mounting in Canada balsam ($ 281), 

 1-2 minutes. 



22. Labeling the preparation ($ 308), 2 

 minutes. 



23. Cataloging the preparation ($ 309), 

 5-10 minutes. 



