Parameter
Comment
Cantilever spring
constant
0.3–0.7 N/m (written on the cantilever box)
Cantilever tip
radius
2–10 nm (written on the cantilever box)
8. Click on Engage to move the cantilever down and approach the
surface in an automated way. Approaching can take some time,
depends on how close the cantilever is to the surface. Next,
AFM will begin to scan the sample.
9. Scans presenting different physical parameters are displayed in
real time (Height, Peak Force Error (Fig. 4a), DMT Modulus
(Fig. 4b), Log DMT Modulus, Adhesion, Deformation, Dissipation, Sneddon Modulus). Below the Height image, two curves,
trace curve (blue) and retrace curve (red), are displayed. If they
do not overlap well, then you should adjust the parameters
described (see Subheading 3.4, step 7).
10. Force Monitor (N/s) is displayed in the right corner. It presents the force curves being recorded during the scan
(extended in blue and retracted in red) (Fig. 4c). Make sure
that the force curves display proper morphology comparing
them to the model curve (Fig. 2b). The elevated part of blue
and red curves should overlap. If they do not align well, then
press auto config in Force monitor on the right. If it does not
help, modify the parameters (see Subheading 3.4, step 7), or
this may suggest problems with the cantilever or the sample.
11. Start with a maximum scan size (150 μm
2 ) and use low
resolution (Samples/Lines: 64 or 128 pixels in X and
Y axes) to record an overview of the sample (topological
image without measuring the forces) (see Note 13).
12. When a place of interest is found, perform a higher resolution
scan (Samples/Line: at least 256 pixels in X and Y axes and at
Low Scan rate) and record the force curves (file with. PFC
format). A higher resolution allows to record more force
curves within small regions making the measurement more
accurate.
13. Further zoom into specific places of interest and record more
high-resolution images and force curves (see Note 14).
14. After the images with force curves are recorded, withdraw the
cantilever.
15. Looking at the objective camera (Fig. 3f), move to another
place on the slide (see Subheading 3.4, steps 8–14) or begin
to scan another slide (see Subheading 3.4, steps 1–14).
Atomic Force Microscopy to Study Cell Wall Mechanics in Plants
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Comment
Cantilever spring
constant
0.3–0.7 N/m (written on the cantilever box)
Cantilever tip
radius
2–10 nm (written on the cantilever box)
8. Click on Engage to move the cantilever down and approach the
surface in an automated way. Approaching can take some time,
depends on how close the cantilever is to the surface. Next,
AFM will begin to scan the sample.
9. Scans presenting different physical parameters are displayed in
real time (Height, Peak Force Error (Fig. 4a), DMT Modulus
(Fig. 4b), Log DMT Modulus, Adhesion, Deformation, Dissipation, Sneddon Modulus). Below the Height image, two curves,
trace curve (blue) and retrace curve (red), are displayed. If they
do not overlap well, then you should adjust the parameters
described (see Subheading 3.4, step 7).
10. Force Monitor (N/s) is displayed in the right corner. It presents the force curves being recorded during the scan
(extended in blue and retracted in red) (Fig. 4c). Make sure
that the force curves display proper morphology comparing
them to the model curve (Fig. 2b). The elevated part of blue
and red curves should overlap. If they do not align well, then
press auto config in Force monitor on the right. If it does not
help, modify the parameters (see Subheading 3.4, step 7), or
this may suggest problems with the cantilever or the sample.
11. Start with a maximum scan size (150 μm
2 ) and use low
resolution (Samples/Lines: 64 or 128 pixels in X and
Y axes) to record an overview of the sample (topological
image without measuring the forces) (see Note 13).
12. When a place of interest is found, perform a higher resolution
scan (Samples/Line: at least 256 pixels in X and Y axes and at
Low Scan rate) and record the force curves (file with. PFC
format). A higher resolution allows to record more force
curves within small regions making the measurement more
accurate.
13. Further zoom into specific places of interest and record more
high-resolution images and force curves (see Note 14).
14. After the images with force curves are recorded, withdraw the
cantilever.
15. Looking at the objective camera (Fig. 3f), move to another
place on the slide (see Subheading 3.4, steps 8–14) or begin
to scan another slide (see Subheading 3.4, steps 1–14).
Atomic Force Microscopy to Study Cell Wall Mechanics in Plants
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