SECTION THREE 



triarylmethane dyes (e.g. light green SF) are slightly soluble in 

 dioxane to produce colourless solutions. That is to say, dioxane 

 appears in some cases to act as a decolorizing agent by com- 

 bining with such dyes. 



Warning.— Care should be taken as Dioxane vapour is toxic. 



Technique: 



1. Transfer tissues directly from the fixative to a well-stoppered 

 specimen jar containing Dioxane with a thin layer of anhydrous 

 calcium chloride over which is placed a circle of surgical or zinc 

 gauze to separate the tissue from the dehydrating agent. Allow 

 the Dioxane to act from three to twenty-four hours, depending 

 upon the size and thickness of the tissue. 



Note: Tissues which have been treated with a fixative such as 

 Miiller or Zenker, containing potass, dichromate, must be washed 

 from two to twelve hours in running water, depending upon the 

 size and the nature of the tissue, before being transferred to Diox- 

 ane. 



2. Transfer to a mixture of equal parts of paraffin wax and Diox- 

 ane for half to one hour in a paraffin embedding oven. 



3. Transfer to pure paraffin wax, allowing a somewhat longer 

 time for impregnation than for tissues cleared by the orthodox 

 method. 



Note: The Dioxane can be used several times provided the 

 calcium chloride is changed. 



ETHYLENE GLYCOL 



A solvent, inflammable when heated, burning with an intense, 

 almost invisible flame; which may also be employed as a de- 

 hydrating and differentiating agent for the Sudan colours, in place 

 of acetone-alcohol, 70% or 50% alcohol ; giving stable solutions, 

 without loss of stain from the lipid particles. 



Technique: 



I. Prepare the staining solution by heating and stirring about 

 075 gm. of the dye with 100 ml. pure anhydrous ethylene glycol 



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