MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



5. Clear in xylol for an hour. 



6. Immerse in a bath of molten paraffin wax for half an hour. 



7. Transfer to a second bath of paraffin wax for an hour. 



8. Complete the infiltration by immersing in a third bath of 

 wax for an hour ; then cast the block and cut sections. 



9. Fix sections to slides ; then remove paraffin wax with xylol. 



10. Rinse in two changes of cellosolve. 



1 1 . Apply the stain ; then wash with water, or alcohol. 



12. Immerse for one to three minutes in each of three changes 

 of cellosolve. 



13. Clear in xylol, benzol, clove oil or cedarwood oil. 



14. Mount in balsam, cristalite or D.P.X. (Lendrum and Kirk- 

 patrick). 



DIOXANE 



For the dehydration and clearing of tissues 



This reagent, which is a colourless inflammable liquid, solidi- 

 fying at 10° C, miscible with water and paraffin wax, alcohol and 

 xylol as well as many other organic solvents of the aliphatic and of 

 the aromatic series, is used and preferred by many workers in place 

 of the orthodox alcohol-xylol-cedarwood oil method for de- 

 hydrating and clearing tissues, as the technique is simpler and 

 quicker and it has the advantage of eliminating brittleness and 

 shrinkage of tissues. It is, however, essential that a reliable brand 

 of Dioxane be employed, as some makes contain relatively large 

 amounts of water, and are therefore unsuitable for histology. 



Warning* — Care should be taken as Dioxane vapour is toxic: 

 it should be used only where ventilation is abundant. 



Technique: 



I. 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. 



36 



