CYTOCHROME OXIDASE 95 



The hydrochloride is favored because it is more stable. 

 Nadi Reagent. Prepare just before using by combining equal vol. 



of the a-naphthol and p-aminodimethylaniline solns. and filtering. 

 Strong Ammonium Molybdate Solution or Dilute Lugol Solution. 



Concentration not stated. 

 Dilute Lithium Carbonate Solution. Concentration not stated. 



PROCEDURE 



1. Fix tissue for two hr. in formalin vapor or in a mixture of 

 10 ml. formalin and 40 ml. 96% alcohol. 



2. Prepare frozen sections and place them on slides which are 

 then laid in a thin layer of nadi reagent in a petri dish. Oxygenation 

 of the fluid is effected by careful agitation. After 1-5 min., rinse in 

 water and examine. 



3. Make the color more permanent by treating for 2-3 min. with 

 dilute Lugol soln. The Lugol soln. converts the blue granules to 

 brown. Washing sections in dilute lithium carbonate restores the 

 blue. Strong ammonium molybtlate soln. has been used instead of 

 Lugol soln. 



4. Counterstain with Bismark brown, safranine or alum carmine 

 and mount in glycerin or glycerin jelly. 



Result. Cytochrome oxidase is supposed to be indicated by the 

 blue coloration. 



Graff Method for Cytochrome Oxidase in Fresh Tissue 

 ("G. Nadi Oxidase") 



The pH of the nadi reagent must be adapted to the requirements 

 of the particular material under investigation. Lison (1936, page 

 274) states that the pH range 7.8 to 8.2 is most suitable for animal 

 tissues and 3.4 to 5.9 for plant material. 



SPECIAL REAGENTS 



a-Naphthol Solution. Prepare a 10% alcoholic soln. and just before 



use dilute 100 times with distilled water. 

 0.12% p-Aminodimethylaniline Hydrochloride. Store in the dark. 

 Nadi Reagent. Prepare just before using by combining equal vol. 



of the diluted a-naphthol soln. and the p-aminodimethylaniline 



soln. 

 Buffered Nadi Reagent. Mix the reagent with the suitable buffer 



