Zou Finrock and Kelly Summers have recommended me to contact you. We are using 8-day old Arabidopsis plants to see of the effects of toxic metals, in the root tips, in particular. They are really hard to work with! Many thanks, Olena
A specifics of the beamline used plays a big role. What is perfectly fine for a partciluar beamline/source may not work for another. The fine details are not always found in the published literature.
It seems embedding your sample in paraffin wax and taking longitudinal sections might be the best way to view the root internal tissue by confocal microscopy.
I hope this helps, and I wish you success in research.