264 Cytoplasmic Elements (chap. 18) 



blesome precipitate with the methyl green. If too much is re- 

 moved, mitochondria will be lightly colored. 



7. Pipette methyl green on slide, watching colors by holding it over 

 white paper: abotit 5 seconds. 



8. Drain off stain, rinse briefly in 95% alcohol. 



9. Dehydrate in absolute alcohol, clear, and mount. 



results: 



mitochondria — bright red 



comments: 



If the methyl green removes all fuchsin, mordanting by dichromate 

 was incomplete. Omit steps 2 and 3, or treat sections for a fe^v seconds 

 with 2% potassium dichromate before staining. 



If fuchsin is so intense that the methyl green removes it imper- 

 fectly, the mordanting was too great. Correct this in steps 2 and 4. 

 If the methyl green washes out, omit rinsing in 95% alcohol; go di- 

 rectly to absolute. 



A solution of aurantia,^ saturated in 70% ethyl alcohol (30 sec- 

 onds) may be used in place of methyl green. Go directly to absolute 

 alcohol. 



Altmann-Benda's Method: (champy-kull modification, mcclung^ 



1939) 



fixation: Champy fluid: 24 hours (page 17). 

 Wash in distilled water: 1 hour. 



Treat 24 hours in: 



pyroligneous acid 50.0 ml. 



chromic acid, 1% aqueous 50.0 ml. 



Mordant in potassium dichromate, 2% aqueous: 3 days. Wash in 

 running water: 24 hours, dehydrate and embed. Cut thin sections, 

 3-4 microns. 



procedure: 



1. Deparaffinize and hydrate slides to water. 



2. Cover slides with Altmann's fluid (page 263). Heat gently but do 

 not boil. Cool and allow to stain 6 minutes. 



3. Pour off stain, and rinse rapidly in distilled ^s'ater. 



* Michrome stains: Edward Gurr, Ltd., London, England, or Griibler stains: Roboz 

 Surgical Instrument Co., Washington, D.C. 



