SULFHYDRYL AND DISULFIDE GROUPS 37 



1. Immerse the fresh tissue in the zinc acetate soln. for a few sec. 

 This will stabilize the red color finally developed, as shown by 

 Giroud and Bulliard (1933). 



2. Add 1 drop of the sodium nitroprusside soln. to a section 

 on a slide. 



3. Add a crystal of ammonium sulfate and a drop of ammonium 

 hydroxide. 



Result. Sulfhydryl compounds such as glutathione produce a 

 red color. 



B. For total sulfhydryl groups 



1. Treat sections of fresh tissue with 10% potassium cyanide 

 for 5-10 min. 

 2.-4. Proceed with steps 1-3 in A. 



C. For protein-bound sulfhydryl groups 



1. Treat sections of fresh tissue with 10% trichloroacetic acid 

 for 15 min. and wash thoroughly in water. 

 2.-4. Proceed with steps 1-3 in A. 



note: The diffusibility of the sulfhydryl compounds formed in B, or liberated 

 in C, makes for particular unreUability in the localization of the groups in 

 the sections. 



Bourne Nitroprusside Test 



SPECIAL REAGENTS 



5% Acetic Acid. 



5% Sodium Nitroprusside Saturated with Ammonium Sidfate. 



Concentrated Ammonium Hydroxide. 



PROCEDURE 



1. Place fresh frozen sections of tissue in hot 5% acetic acid 

 for 30-90 sec. 



2. Pour off the acid and replace with nitroprusside-ammonium 

 sulfate soln. for 2 min. 



3. Add a few drops of ammonium hydroxide and examine at once. 

 Result. A purplish-blue color indicates sulfhydryl compounds. 



Hammett and Chapman Nitroprusside Test 



SPECIAL REAGENTS 



27-29% Ammonium Hydroxide. 



