[Arabidopsis] avoiding sample movement in confocal microscope

[Damiani]

Dear members,

Using confocal microscopy I want to see fluorescence appear after 
treatment of roots with various solutions.
The problem is that the treatment makes the sample move on the slide. 
Thus, I cannot follow the fluorescence on the same focal plan.

Is anybody know how to fix a sample on a slide to avoid all the 
movements of the sample?

Thank you.

Isabelle