MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



12. Clear in xylol. 



13. Mount in Cristalite or Canada balsam in xylol and examine 

 under the oil immersion objective. 



Results: 



Nucleoli, brilliant red. Chromosomes during metaphase and 

 anaphase are stained a bright red and stand out sharply against a 

 dark background ; during prophase and telophase the chromosomes 

 are considerably darker. Trabants are usually red and are attached 

 to the chromosomes by a black thread. 



Note: This technique gives the best results after a killing fluid 

 containing picric acid, but chromic acid fixatives also give good 

 results. 



Reference : Plant Microtechnique (ist ed., p. 75) by D. A. Johansen, by courtesy 

 of the McGraw-Hill Book Co. 



IRON ACETO CARMINE (Belling) 

 For chromosomes in microsporocytes 



Solutions required: 



Iron Aceto Carmine [Belling) 



Acetic acid 50% aqueous . . . . 100 ml. 



Carmine, powdered . . . . i gm. 



Boil under reflux condenser for half an hour. 

 Cool and filter. 



Add a few drops of ferric hydrate in 50% 

 acetic acid. 



Technique: 



Temporary preparations : 



1 . Anther smears are made on slides by teasing and squashing. 



2. Place a drop of the stain on a smear ; then cover with a cover- 

 slip. 



3. Place slide, coverslip facing upwards over a corner of a tripod 

 and heat gently until steam rises from the edges of the coverslip. 



4. Examine under the microscope at once. 



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