STAINING, PRACTICAL AND THEORETICAL 



Notes: 



{a) Among strongly erythrophile elements are the nucleoli of 

 cells, probably because of their histone component: red blood 

 corpuscles and neurokeratin. The oldest fibres formed by fibro- 

 proteins, e.g. keratin and collagen fibres, are strongly erythrophile, 

 the youngest fibres being weakly erythrophile. Indeed, there 

 appears to be a tendency for erythrophila to increase with age in 

 all erythrophilic tissues. 



As a general rule, not yet certain, the Falg method is prefer- 

 able for adult gland tissues. 



(6) The faviolic acids have the remarkable property that they 

 intensify the reaction of already birefringent material to polarized 

 light. As a consequence of this, polarized light can now be used 

 for thinner sections than previously, and for the detection of 

 birefringent elements at the limits of the optical microscope. 



[c) A further remarkable property of the faviolic acids is that 

 they intensify the differentiation of structures under phase- 

 contrast. Normally stains reduce this contrast. 



{d) Reference should be made to pages 76-90 of this book and 

 to the authors' original papers for further information on the 

 mechanism of the Faviol staining. 



2. STANDARD FAVIOL METHOD 



A simple universal trichrome staining method applicable to 

 animal and plant histology and cytology. 



Solutions required: 



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

 Acetic acid, 4% aqueous . . 100 ml, 



(See note {a), page 199.) 



B. Acetic acid, 2% aqueous 



C. Violamine 3B (Michrome No. 



161), 1% aqueous . . . . i2'5 ml. 



Sun yellow G (Michrome No. 



720), 1% aqueous . . . . i2'5 ml. 

 Water 75 ml. 



(See notes {a) and {d), pages 205-6.) 



204 



