SECTION TWO 



5. Wash in distilled water for five minutes. 



6. Counterstain in the Luxol fast blue (solution F) for fifteen 

 to sixty seconds. 



7. Mount in glycerine jelly, or better in Aquamount, and seal 

 the edges of the coverslips with Laktoseal. 



Results: 



The following are stained black: 



Degenerating myelin, depot fat, fat droplets in fatty liver, and 

 lipid in the zona fasciculata of the adrenal. 



The following are stained red: 



Normally myelin of the central or peripheral nervous systems, 

 sphingomyelin storage granules in Niemann-Pick's disease, and 

 lipid droplets in the zona glomerulosa of the adrenal. 



The following are stained light red: 



The erythrocyte envelope, and cerebroside storage granules in 

 Gaucher's disease. 



The following are stained in shades of blue: 



The stored lipid granules, which are probably ganglioside, of 

 Tay-Sach's disease; glial fibres and connective tissues. 



The axon is unstained. 



Notes: 



(a) The author states that from chemical evidence it may be 

 deduced that since normal myelin is hydrophilic, it is permeable 

 to electrolytes such as potassium chlorate, and that the chlorate 

 absorbed prevents the reduction of osmium tetroxide (to lower 

 oxides which are black) by the unsaturated groups of normal 

 myelin lipids. Osmium tetroxide itself is soluble in both hydro- 

 philic and hydrophobic lipids. Therefore, osmium tetroxide is 

 permeable to unsaturated hydrophobic lipids which will not 

 accept the potassium chlorate, and it is these lipids that reduce 

 the osmium tetroxide to give the black stain observed in the 

 sections. 



(6) The author states that the red reaction due to osmium- a- 

 naphthylamine chelate indicates that lipids so stained are hydro- 

 philic. 



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