SECTION THREE 



Technique: 



1. Fix tissues in Bouin or Flemming and embed in paraffin wax. 



2. Stain in a freshly prepared, unfiltered, alcoholic solution of 

 chlorazol black (as above) for five to ten minutes. 



3. Drain off excess stain; dehydrate; clear in xylol and mount. 



Results: 



Vascular plant: Cell wall, jet black; cytoplasm, greyish green; 

 nuclei, yellowish green; nucleoli, deep amber to dark green. 



Fern leaf: Cell wall, intense black; epidermis walls, heavy 

 black; cytoplasm, light amber; nuclei, green; nucleoli, dark 

 green; plastids, grey; suberized walls of midrib, dark amber; 

 veins, dark amber. 



Notes: 



(a) The stain may be incorporated with Lactophenol. 



{h) Benzyl alcohol may be used as a solvent of the stain, in 

 which case the results are somewhat different. 



{c) If it is desired to differentiate the stain dilute " Milton '* 

 (a proprietary antiseptic) may be used. 



CHLORAZOL PAPER BROWN, B 



For plant tissues 



Material may be stained overnight, but in many cases, e.g. where 

 the delicate cell contents are not germane to investigation, the 

 equivalent depth of staining will be produced by boiling for one 

 to two minutes in the staining solution. By employing the boiling 

 technique finished slides can be obtained in five minutes. 



Solution required: 



Chlorazol Paper Brown,^ B, satur- 

 ated aqueous. 



Technique: 



I. Sections are stained overnight in a saturated aqueous solution 

 (about 3%) of the stain, or by boiling in this staining solution for 

 one to two minutes. 



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