Staining & mounting roots

The next step in the analysis of the roots harvested from the MIP is staining and mounting. The 0.15 grams of roots from each corn plant grown in our different treatments of soil was placed in a small cassette and then placed in boiling 10 % KOH for 3-5 minutes. The potassium hydroxide clears the roots of the cellular contents of their cortical cells so that the fungi, which lives inside the roots, can be seen better. The fungus isn't killed because the fungus is made of chitin which is very recalcitrant and resists breakdown. 

 KOH and ink in vinegar solution

Roots in boiling KOH

The next step after the roots have been boiled in KOH is to place them in boiling 5 % ink in vinegar solution for 3 minutes. After this step has been completed, the fungi inside of the roots will have been stained and will be completely visible under a microscope. The roots are then mounted in PVLG on a microscope slide to be viewed. 

Dr. Chaudhary's perfect example slide

All of our roots stained and mounted

And finally our roots are ready to be examined for mycorrhizal fungi!