Special Stains - Methyl Green Pyronin

This method utilises mild hydrolysis with NHCl to break the purine-deoxyribose bond resulting in exposed  aldehydes which are then demonstrated by Schiff's reagent.  Elements containing DNA are stained magenta colour.  This is a reliable and specific method for DNA.

This technique is not used as much as it used to be since more specific DNA work has taken over much of the previous role, but it is still a helpful technique for DNA detection.

The main method for carrying out this technique is listed below

1.      Take section to distilled water

2.      Rinse briefly in cold N Hydrochloric acid

3.      Transfer to preheated N Hydrochloric acid at 60°C    - 10 mins

4.      Rinse in distilled water

5.      Transfer to Schiff's reagent - 30 mins to 1 hour

6.      Rinse in three changes of freshly prepared Sulphite rinse

7.      Rinse in water

8.      Counterstain in Light Green - 1-2 mins

9.      Rinse then dehydrate, clear and mount

Result

DNA	Magenta
Cytoplasm	Green

Photo x10 Methyl Green