Thanks for all replied to my post. 
Indeed I have no idea about using EM to observe tissue sections. What I want to do is using EM to trace a particle which is belived to be taken up by macrophage/DC in lymph node, the tracer have been said can be observed under EM. So I need a protocol in which I can learn from tissue removal through all steps to embedding.
I only have a machine can cut sections to 5 micrometer thick. But maybe I can get these material include grids from EM technologist.