STAINING, PRACTICAL AND THEORETICAL 



Technique: 



1. Blocks not exceeding 3 mm. in thickness of fresh tissue from 

 the hippocampus major and cerebellum should be fixed in Zenker 

 for twelve to twenty-four hours. 



2. Remove mercurial precipitate with iodine in alcohol by the 

 usual method (see page 496) ; then wash in running water for three 

 to six hours. 



3. Dehydrate in dioxane {see page 512) and embed in paraffin 

 wax. 



4. Sections not more than 4/^ thick are mounted on slides and 

 brought down to distilled water. 



5. Flood slides with Solution C and steam gently for five min- 

 utes ; then cool and wash rapidly in tap water. 



6. Decolorize and differentiate each section separately by 

 waving the slide gently in a jar of 90% alcohol until the section 

 assumes a faint violet colour. 



7. Dehydrate rapidly in 95% ^^^ absolute alcohol; clear in 

 xylol and mount. 



Results: 



Negri bodies, deep red; granular inclusions, dark blue; nucle- 

 oli, bluish black; cytoplasm, bluish violet; erythrocytes, dull 

 reddish brown. 



Reference: Scheifstein, J. (1937). 



METHYLENE BLUE - BASIC FUCHSIN 

 For rickettsia in sections 



Solutions required: 



A. Methylene blue 1% aqueous. 



B. Basic fuchsin 0-5% aqueous, in phosphate 



buffer pH 7-0. 



C. Citric acid 0-5% aqueous. 



302 



