276 Cytoplasmic Elements (chap. 18) 



comments: 



Treatment with acetic acid enhances differentiation and reduces 

 fluorescence of normal tissue without affecting the fluorescence of 

 amyloid. Vassar and Culling suggest that the nuclear fluorescence 

 can be quenched by prestaining with hematoxylin (2 minutes), then 

 proceeding with step 2 above. 



For details concerning fluorescent microscope and equipment, see 

 page 102. 



Mast Cell Staining 



Mast cells are of common occurrence in connective tissue. Because 

 of their cytoplasmic granules, however, staining methods for these cells 

 have been included in this cytoplasmic element section. The specific 

 staining of these granules is the primary means of identification of 

 mast cells. 



Neutral Red (allen, 1960) 

 fixation: 10% formalin 



solution: 



neutral red, C.I. 50040 0.5 gm. 



50% ethyl alcohol 100.0 ml. 



procedure: 



1. Deparaffinize and run slides down to 70% alcohol. 



2. Stain in alum hematoxylin: 3 minutes. 



3. Wash, blue, and wash. 



4. Stain in neutral red: 10 minutes. 



5. Differentiate in 70% alcohol: 2-10 minutes. 



6. Dehydrate in 95% alcohol: 3 minutes. 



7. Dehydrate in 7z-butyl alcohol, 2 changes: 5-10 minutes in each. 



8. Clear and mount. 



results: 



mast cell granules — red 

 cartilage matrix — red 

 nuclei — blue 



comments: 



Color is paler tlian with metachromatic methods, page 281. 



