Mushroom tissue analysis?

Hi all,

I recently found an old maple tree with tons of oysters (pleurotus ostreatus) growing near the top. The attached picture only shows a small portion. The tree is in an urban area.

I'm curious if anyone knows of a way to send some of the mushrooms in for tissue analysis, to know if they're accumulating dangerous quantities of contaminants. We do this for plants all the time, but not necessarily fungi!

I don't know, but I would think that the same lab could analyze the mushroom as well as the plant.
john S
PDX OR