Hi!

Propidium iodide should work. It is red, it stains DNA, and it does not penetrate living cells, so you will be able to visualize eDNA.

Thanks Alexander for your answer. Yes that is the only one I found in the literature however I want to also try with another stain to see what will work best.

Hi

I'm not sure if you'll be able to find a dye with blue fluorescence unless you use UV and it's a bad idea for living biofilms. I'm agree with Alexander, the best options are phenantridiniums.

best regards

Thank you Francesc for your advice. I will go ahead with propidium iodide then.