There is a special procedure of preparing biological samples for SEM. One can easily find it on the web. I've added two links to descriptions of such procedures.

http://research.jcu.edu.au/enabling/aac/cairns-aac/biological-sample-preparation-for-the-sem

https://www.emsdiasum.com/microscopy/technical/datasheet/critical_drying.aspx

Information that you provide is very helpful at all. Thank you very much. But I want to ask about the procedure that you would suggest to me that if the procedure can be applied to the mycelium is dried prior to the freeze drier ??

I agree with Anaële that freeze drying is not the best technique for SEM specimen preparation. But it does not mean your specimens are lost for you – sometimes freeze drying gives acceptable results. And yes, just coat them and observe. Good luck.

Dear Anaele Simon and Vladimir Dusevich thank you very much for your answer.

Best Regards

Why are samples that have been dried mycelium gives poor results ??