the force curves can be compared within the same image, e.g.,
concave (e) vs. convex (x) regions of the wall (see Note 19).
19. To be able to compare the properties among different images,
transform the MPa differences to percentage (see Note 20).
4 Notes
1. Always use the same leaf when comparing different plants
(counting from cotyledons, older leaves to the small primordia
on the meristem). Use a representative middle region of the
leaf, which reflects the most common features of epidermal
pavement cells. I compare the middle region of the third leaf
[33, 40] and I use 10 individual plants within the same line.
2. Leaf pieces should be no bigger than 2 mm
2 , smaller is better
for the fixative to penetrate.
3. Orient all the samples in the same way to remember which one
is the adaxial and abaxial side of the leaf. The leaf pieces need to
be as flat as possible in order to access the anticlinal walls in the
right plane. Cut small cubes no bigger than 8 mm
2 and move
the cubes to the vials filled with water. LMP agarose also
facilitates the handling of the sample when it needs to be
moved through different solutions of alcohol and resin.
4. Use a sharp needle to indent the resin and see if it is stiff. The
resin should polymerize equally in different regions. This is
very important in measuring the local properties of the sample.
5. The trimmed part will be faced to the knife, it should be sharp
and not exceeding the length of the knife (usually no bigger
than 2 mm). Pay attention to properly orienting the sample in
the way that the sections of the cells are parallel to the knife and
are not oblique. Use only flat (non-wrinkling) and stable
sections.
6. Sections for the mechanical measurements cannot be stained.
The sections are transparent, so use a permanent marker (below
the slide where sections are) to facilitate their localization under
the microscope. Due to the limited scan size, it is good to have
a single section in the middle of a slide.
7. Use low temperature (40–50
C) to not overheat the sample.
Use compressed air to make sure that the sections are
adhering well.
8. Handle the cantilever with care, using tweezers with nonmetallic tips (Fig. 3a). Resin-embedded sections are much stiffer
than live material samples and require harder cantilevers with
sharp tips, which penetrate the sample well to access the details
366
Mateusz Majda
concave (e) vs. convex (x) regions of the wall (see Note 19).
19. To be able to compare the properties among different images,
transform the MPa differences to percentage (see Note 20).
4 Notes
1. Always use the same leaf when comparing different plants
(counting from cotyledons, older leaves to the small primordia
on the meristem). Use a representative middle region of the
leaf, which reflects the most common features of epidermal
pavement cells. I compare the middle region of the third leaf
[33, 40] and I use 10 individual plants within the same line.
2. Leaf pieces should be no bigger than 2 mm
2 , smaller is better
for the fixative to penetrate.
3. Orient all the samples in the same way to remember which one
is the adaxial and abaxial side of the leaf. The leaf pieces need to
be as flat as possible in order to access the anticlinal walls in the
right plane. Cut small cubes no bigger than 8 mm
2 and move
the cubes to the vials filled with water. LMP agarose also
facilitates the handling of the sample when it needs to be
moved through different solutions of alcohol and resin.
4. Use a sharp needle to indent the resin and see if it is stiff. The
resin should polymerize equally in different regions. This is
very important in measuring the local properties of the sample.
5. The trimmed part will be faced to the knife, it should be sharp
and not exceeding the length of the knife (usually no bigger
than 2 mm). Pay attention to properly orienting the sample in
the way that the sections of the cells are parallel to the knife and
are not oblique. Use only flat (non-wrinkling) and stable
sections.
6. Sections for the mechanical measurements cannot be stained.
The sections are transparent, so use a permanent marker (below
the slide where sections are) to facilitate their localization under
the microscope. Due to the limited scan size, it is good to have
a single section in the middle of a slide.
7. Use low temperature (40–50
C) to not overheat the sample.
Use compressed air to make sure that the sections are
adhering well.
8. Handle the cantilever with care, using tweezers with nonmetallic tips (Fig. 3a). Resin-embedded sections are much stiffer
than live material samples and require harder cantilevers with
sharp tips, which penetrate the sample well to access the details
366
Mateusz Majda