STAINING, PRACTICAL AND THEORETICAL 



Technique: 



1. Fix pieces of tissue in formol sublimate and embed in 

 paraffin wax. 



Note: The author states that formalin-fixation gives good 

 results, but mercurial fixatives are superior, and a good general 

 routine is to fix in io% formol-saline. In the latter case the 

 trimmed blocks should be immersed in a mercurial mixture for 

 two hours before processing in the histokine or autotechnicon. 



2. Carry paraffin sections through to water. 



3. Treat for the removal of mercurial precipitate, 



4. Stain in a mixture of equal volumes of solutions A and B 

 for five to fifteen minutes. 



5. Differentiate in acid alcohol (solution C). 



6. Blue in tap water. 



7. Immerse in solution E for one minute. 



8. Wash in running water for five to ten minutes, controlling 

 by microscopic examination at intervals until only the erythrocytes 

 are coloured yellow. 



9. Immerse in solution J for two minutes. 



10. Immerse for one minute in each of three changes of 1% 

 acetic acid. 



1 1 . Rinse in water. 



12. Dehydrate through the usual graded alcohols. 



13. Clear in xylol. 



14. Mount in D.P.X. or Clearmount or Michrome mountant. 



Results: 



Erythrocytes: brilliant orange-yellow. Fibrin: orange-red or 

 red. Cytoplasm of smooth muscle: deep purplish red. Epithelial 

 cytoplasm varies from red to green. Collagen: clear green. 



Notes: 



(a) No special claim is made for this technique as a research 

 tool. Its outstanding merits, according to the author, are speed 

 and ease of operation and the fact that the need for microscopic 

 control is reduced to the minimum. 



(b) The important contrasts between smooth muscle and 

 collagen, and between fibrin and erythrocytes are said to be 

 consistently demonstrated, and it is the consistency of the staining 



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