[Histonet] Karnovsky and Roots stain

[Nicole Cosenza]

I am looking into a project involving motor end plate staining. 
Literature that I've found continually references Karnovsky and Roots 
from the 60s.   However the papers are not supplying all the details.

Does anyone do AchE staining by this method on fresh frozen, unfixed 
tissue sections? If so, can I get a more detailed protocol  (fixation 
steps, washes, etc)?