SECTION TWO 



13. Add 0-5 ml. of the acetic aniline blue (Solution F above) to 

 the phosphomolybdic acid on the slide and mix by rocking the 

 slide gently. Allow this mixture to act for five minutes. 



14. Pour off excess liquid and rinse in distilled water. 



15. Immerse in phosphomolybdic acid solution again, for five 

 minutes. 



16. Transfer to i % acetic acid and leave therein for five minutes. 



17. Wash in distilled water. 



18. Dehydrate in 95% alcohol, followed by absolute alcohol; 

 clear in xylol ; mount. 



Results: 



Collagen, deep blue. Neuroglia fibrils, red. Nuclei, black. 

 Argentaffin granules, black or red. 



METHYL BLUE - EOSIN (Mann) 



For demonstrating the various types of cells in the anterior 



lobe of the pituitary and for the study of the relationship 



and development of the blood vessels 



Solution required: 

 Methyl Blue-Eosin (Mann's stain). 



Technique: 



1 . Paraffin sections of tissues which have been fixed in a fluid con- 

 taining mercuric chloride are mounted on slides and treated by the 

 standard technique for the removal of mercuric precipitate (see 

 page 28). 



2. Bring the sections down to distilled water; then stain for a 

 quarter of an hour to two hours (the longer time is required if it is 

 desired to demonstrate anterior lobe of pituitary). 



3. Wash and differentiate in tap water. 



4. Dehydrate rapidly with two changes of absolute alcohol. 



5. Clear in xylol ; mount in xylol balsam and examine under the 

 low power, as the stain is too diffuse for critical high power work. 



157 



