68 Freezing Method, (chap.. 6) 



An alternate method can be used and is perhaps preferred by some. 



1. Place frozen section in a small amount of stain, 5-10 seconds. 



2. Transfer with glass rod into tap or distilled water to remove excess 

 stain, 5-10 seconds or longer. 



3. Mount on slide, blot off excess water, add mountant and cover glass. 



This method is not recommended for paraffin sections, only for fresh 

 or frozen ones; differential staining is lost in the former. In order to 

 preserve cytoplasmic staining, sections cannot be dehydrated; alcohol 

 decolorizes cytoplasmic structures and only the nucleus will retain ap- 

 preciable amounts of stain. All mounts are temporary and should be 

 sealed if preservation for several days is desirable. (The stain solution 

 can also be used for sex chromatin staining, page .S62.) 



Results (of Pinacyanole Staining) 



chromatin — well-differentiated blue to reddish blue 



connective tissue — pink 



elastic tissue — dark violet 



muscle — violet to purple 



plasma cells — red granuloplasm 



hemosiderin — orange 



hemoglobin, neutrophil and eosinophil granules — unstained 



neutral fat — colorless to faint bluish violet 



lipoids — bluish violet to purple 



amyloid — carmine red 



Humphrey's (1936) Method (Perhaps the Fastest) 



1. Place section on a slide and wipe off excess water. 



2. Add 1 drop of 0.5% brilliant cresyl blue in saline. 



3. Cover with cover glass and examine. Never a permanent mount. 



Thionin or Toluidine Blue Method 



1. Remove section from water to a solution of either 0.5% thionin or 

 toluidine blue O in 20% ethyl alcohol plus a few drops of glacial 

 acetic acid: 30 seconds. 



2. Rinse in water and float on slide. 



3. Drain off excess water, blot around edges of section, add drop of 

 glycerine and cover glass. This is not a permanent slide. 



