Equilibrate root in 45% acetic acid.
Cut off root cap with a razor blade.
Cut off a somewhat thin cross sectional slice, put on slide with a cover slip and a drop of acetic acid.
Slide the razor under one corner of the cover slip and gently heat over a flame.
Tap a few times with the back of a probe and flame again.
Tap more times in a circular pattern.
Cover with filter paper and lightly press with thumb.