Arginiiie Test 353 



comment: 



Freeze-dried and embedded tissues give a good Dopa reaction. 



Arginine Test 



The arginine reaction uses the reaction of rt-naphthol with guanidine 

 derivatives in the presence of hypochlorite or hypobromite to produce 

 an orange-red color. The reaction proceeds ^vith guanidine derivatives 

 in which one hydrogen atom of one of amino groups is substituted by 

 alkyl, fatty acid or cyano radical. Proteins containing arginine give the 

 color, and in tissue fixed by ordinary methods the reaction is specific 

 for protein-bound arginine and other guanidine derivatives such as 

 glycocyamine or agmatine. Guanidine, urea, creatine, creatinine, and 

 amino acids, other than arginine, do not give the color. 



Thomas (1950); Liebman (1951) 

 fixation: Bouin's or Stieve's. 



solutions: 



fl-Naphthol stock solution: 



rt-naphthol (Eastman #170) 1.0 gm. 



absolute ethyl alcohol 100.0 ml. 



Keep in refrigerator. 



W^orking solution: 



stock solution 5.0 ml. 



distilled water 100.0 ml. 



Hypochlorite and potassium hydroxide: 



N sodium hypochlorite 15.0 ml. 



distilled water 80.0 ml. 



N jDotassium hydroxide 5.0 ml. 



Urea, potassium hydroxide: 



urea 10.0 gm. 



distilled water 15.0 ml. 



N potassium hydroxide 5.0 ml. 



Shake until urea is in solution, add: 



tertiary butyl alcohol, anhydrous 70.0 ml. 



procedure: 



Reagents above are kept in ice bath and allowed to cool ^vell before 



