30 NUCLEAR STAINS. 



Either solution will stain Alcohol-hardened tissue in 30 

 minutes. Tissues hardened in the Chromates require 3 to 4 

 hours. When washed in 90 p. c. Alcohol (without acid), 

 cleared and mounted in Balsam, good differential staining 

 results. If, however, sections be left in the stain for 24 

 hours as recommended by some writers, overstaining takes 

 place, and treatment with Acidulated Alcohol becomes neces- 

 sary. This method also yields very good results, perhaps 

 slightly better than the previous one, but occupies a much 

 longer time. 



FOR GENERAL USE. 



Sections are stained with Lithium or Borax Carmine for 

 15 minutes to 2 hours according to the nature of the tissue 

 and the depth of stain required, then treated with Acidulated 

 Alcohol to decolourise the ground tissue, and so bring out 

 the nuclei, washed in 90 p. c. Alcohol, cleared and mounted 

 in Balsam. 



As an example, a section of skin stained in Lithium Car- 

 mine for 50 minutes will be well differentiated by treatment 

 with 1 p. c. Acidulated Alcohol for 10 15 minutes; when 

 stained in Alcoholic Borax Carmine for 2 hours, acid wash- 

 ing for 4 minutes is sufficient for most purposes. 



If Alum Carmine be used for the same length of time, 

 treatment in Acidulated Alcohol is not required. The 

 stained sections are first washed in water, then in 90 p. c. 

 Alcohol, cleared and mounted in Balsam. 



COUNTERSTAINING. See Plasmatic Stains. 



(i.) AMMONIA CARMINE. 



All Alkaline Solutions are good solvents for Carmine, arid 



