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AFM Force Curves Module for MountainsMap
AFM force curve analysis with automatic detection of adhesion
points, WLC models & statistics
Automatic pre-processing
Force curve visualization
Automatic event detection and parameter calculation
Wormlike chain (WLC) models
Analysis of series of force curves
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AFM Force Curves Module for MountainsMap
Automatic pre-processing
Denoising, base line normalization and calibration
By default a Minidoc (automatic routine) is applied
when a force curve or series of force curves is
loaded. The Minidoc prepares the force curve or
series for analysis. All pre-processing steps are
displayed in the analysis workflow. They can be
fine tuned if necessary.
Denoising
A median or Gaussian filter is applied with a
minimum of 2 points and a theoretical maximum
of 1249 points.
Baseline normalization
Baseline normalization does two things.
It
automatically sets the origin of the force curve
plot. It also aligns zero deflection zones on the
approach and retract curves with the origin.
There are automatic base line normalization
strategies for straight line, oscillating or curved
approach and retract curves.
Base line
normalization can also be carried out manually.
Calibration
Calibration provides two parameters required for
analyzing force curves: sensitivity and the spring
constant. If these parameters are not specified in
the force curve measurement files then they can
be set in Mountains.
Sensitivity (of the cantilever or more precisely of
the photodetector) is required to convert the
deflection in volts (V) into deflection in
nanometers (nm). It can be set directly by the user
(for example based on cantilever specifications).
It can also be calculated automatically with
respect to the contact zone (with slope -1) of a
representative force curve measurement of a hard
surface.
The spring constant is required to convert
deflection in nanometers (nm) into force in
nanonewtons (nN).
It can be calculated
automatically in Mountains after the sensitivity
parameter has been set.
Baseline normalization automatically sets the origin (0,0) and aligns the approach and
retract curves in the colored zones.
Interactive selection of the contact zone (with slope -1) used to calculate the sensitivity and
spring constant parameters
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AFM Force Curves Module for MountainsMap
Force curve and series of force curve visualization and analysis
Adhesion events, protein unfolding, WLC models, full set of parameters
Force curve axes and visualization
Adhesion event parameters
Axis units are selected as follows:
X axis: Distance (nm), Separation (nm) or Time (s)
Z axis: Deflection (V), Deflection (nm) or Force
(nN)
Numerous options are available for customizing
the way force curves are presented graphically.
Fore example, you can zoom in/out on any zone
on a force curve and work in full screen mode.
Adhesion event parameters include:
• Distance (nm), Separation (nm) or Time (s)
• Deflection (V), Deflection (nm) or Force (nN)
• Slope
If there is more than one adhesion event then
differences in the values of parameters between
consecutive events are also calculated.
Interactive adhesion event definition
You can define one or more adhesion events
interactively: add event cursors to the approach
curve or the retract curve with a single click and
then drag them to event locations.
Automatic single adhesion event detection
An event cursor can be located automatically at
the site of the most significant event.
Automatic protein unfolding event
detection
Protein
unfolding
events
are
detected
automatically on the retract curve in accordance
with the WLC (worm line chain) model which is
fitted to each event cursor.
Protein unfolding parameters
Protein unfolding event parameters include:
• WLC (wormlike chain) model
• Persistence length
• Contour length
Series of force curves
Series of force curves are visualized as a series of
overlaid curves. You can walk through the curves
in the series using forward and back buttons.
Parameters are calculated for the currently
selected curve.
Force curves in a series can also be visualized on a
grid.
Statistics
(control
charts,
scatter
plots,
histograms) can be displayed for any specified
event parameter(s).
Protein unfolding: force-distance curve, WLC model and parameters
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AFM Force Curves Module for MountainsMap
Selected features
AFM Force Curves Module for MountainsMap®
Instrument compatibility
The AFM Force Curves module analyzes force curves measured by
instruments from the following manufacturers:
• Agilent Technology (Molecular Imaging)
• Asylum Research
• Bruker Nano (Veeco)
• Nanosurf
• NT-MDT
• RHK.
• Automatic force curve preprocessing with interactive fine tuning if
Automated pre-processing
required
• Denoising (median and Gaussian filters)
• Base line normalization (zero deflection zone)
• Calibration (sensitivity and spring constant)
•Display/hide approach or retract curves
Force curve visualization and axis units
•Customize colors in force curve graphics
•Display/hide force curve data points
•Zoom in/out on any zone on a force curve
•Work in full screen mode
•Set X axis units: Distance (nm), Separation (nm) or Time (s)
•Set Z axis units: Deflection (V), Deflection (nm), Force (nN)
• Add event cursors to curves and drag them to event locations
Interactive adhesion event definition
Automatic single adhesion event detection • Automatically locate event cursor at the site of the most significant
event.
• Detection of protein unfolding events on the retract curve in accordance
Automatic protein unfolding event
with the WLC (wormlike chain) model which is fitted to each event cursor.
detection
• Distance (nm), Separation (nm) or Time (s)
Adhesion event parameters
• Deflection (V), Deflection (nm) or Force (nN)
• Slope
• Distance difference (nm), Separation difference (nm) or Time difference
(s) between consecutive events
• Deflection difference (V), Deflection difference (nm) or Force difference
(nN) between consecutive events
Additional protein unfolding parameters • Persistence length (WLC model)
• Contour length (WLC model)
• Series overlay view
Series of force curves visualization and
• Select a curve in the series using forward and back buttons, display
analysis including statistics
parameters for the current curve
• Series grid view
• Statistics (control charts, scatter plots, histograms) can be displayed for
any specified event parameter(s).
• Export data to an Excel-compatible file.
Data export
Digital Surf Head Office & R&D Center
16 rue Lavoisier,
25000 Besançon, France
Tel +33 3 81 50 48 00
[email protected] - www.digitalsurf.com
© 1996-2016 Digital Surf. All rights reserved. Specifications subject to change without prior notice.
Doc Revision: 20160623