STAINING, PRACTICAL AND THEORETICAL 



THE FALGIC ACID REACTIONS 



(M. A. MacConaill & E. Gurr) 



I. FALG METHOD 



A simple universal polychrome staining method applicable to 

 animal and plant tissues. 



Solutions required: 



A. Acid fuchsin (Michrome No. 5) 0-5 gm. 

 Acetic acid, 4% aqueous . . 100 ml. 



(See note {a), page 199.) 



B. Light green (Michrome No. 240) 0-125 g"^- 

 Water 100 ml. 



Technique: 



1. Stain sections or smears in solution A for five minutes. 



2. Wash in water for five minutes. 



3. Stain in solution B for five minutes. 



4. Wash in water for five minutes. 



5. Dehydrate through the usual graded alcohols. 



6. Clear in xylol. 



7. Mount in D.P.X., Emexel, Clearmount or Canada balsam 

 in xylol. 



Results: 



A polychrome picture in shades of red, violet and blue is 

 produced. Nuclei and chromosomes can easily be distinguished 

 even with a x 10 objective. Erythrocytes are stained scarlet. 

 Neurokeratin of myelinated nerve fibres; odontoblastic fibres of 

 dentine; the most superficial fibres of stratum corneum of skin 

 and other cornified epitheha are also stained red. Both in animal 

 and in plant cells, the nucleus as a whole either exhibits a bright 

 blue staining or it is unstained (clear nucleoplasm). The nucleolus, 

 in the resting stages between mitosis, is, however, stained a bright 

 red. During mitosis, the bright red nucleolus disappears and 

 is replaced by mauve or violet chromosomes. The colour of 

 these chromosomes contrasts so markedly with the blue of the 

 cytoplasm, that a mitotic nucleus can be distinguished, as stated 

 above, even with a x 10 objective. 



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