MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



7. Immerse for three to five minutes in Solution F ; then wash 

 thoroughly in distilled water. 



8. Counterstain overnight in Solution G. 



9. Wash thoroughly in distilled water then immerse in Solution 

 H for thirty minutes. 



10. Without washing transfer section to diluted Solution I for 

 one hour; then wash with 70% alcohol and differentiate the 

 counterstain in 95% alcohol. 



11. Transfer to normal butyl alcohol; clear in cedarwood oil 

 and mount. 



Results: 



Nerve fibres and neurofibrils, blue-black. Nissl bodies, pale 

 blue. Nuclei, blue-black with silver and gold if a higher percen- 

 tage of pyridine was used in solution. Myelin sheaths, bright 

 yellow. Connective tissues, various shades of blue and green. 



PURPURIN 

 For calcium deposits in pathological tissues 



Solutions required: 



A. Purpurin, saturated in absolute alcohol (about 0*7%). 



B. Sodium chloride, reagent grade, 0-75% aqueous. 



Technique: 



1. Fix material in 90% alcohol. 



2. Dehydrate; clear; embed in paraffin wax. 



3. Fix sections to slides; de-wax and pass through the usual 

 descending grades of alcohol to distilled water. 



4. Stain in the purpurin solution for about ten minutes. 



5. Immerse in sodium chloride solution for about five minutes. 



6. Rinse with 70% alcohol until the stain ceases to come away 

 in clouds. 



7. Rinse with 90% alcohol and dehydrate with absolute alcohol. 



8. Clear in xylol and mount in balsam. 



Results: 



Calcium deposits are stained red. 



192 



