1. Cells Stiffen for Cytokines
Richard Newton, Daniel J. Müller 
Cell Chemical Biology 
Volume 25, Issue 5, Pages (May 2018)
DOI: /j.chembiol
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2. Figure 1 Overview of the FD-Based AFM
(A) Schematic of the combined optical and atomic force microscopy set up. The stylus of a microcantilever is used to contour the sample surface, quantify mechanical properties and measure biomolecular interactions. Optical imaging of the sample is possible using an inverted light microscope. Relative humidity, pH, and temperature of the sample are controlled by an incubation chamber (not shown) that retains sample access to both force and optical imaging. Inset: the stylus at the free end of a flexible cantilever is periodically brought into and out of contact with the sample.
(B) Representation of a force-time curve (red) measured using a functionalized AFM cantilever. The curve is annotated with the first mode of cantilever bending in different regions of the curve.
(Bi) The cantilever approaches the sample surface and is driven into the sample. The rapidity with which the cantilever deflects is a function of the stiffness of the sample.
(Bii) The cantilever is most deflected once a predefined force is reached. While in proximity with the sample, the ligand grafted to the stylus can interact with the sample surface.
(Biii) The cantilever withdraws from the sample surface and if the grafted ligand has bound its receptor, the distensible linker (depicted in magenta) is stretched.
(Biv) The linker is mechanically pulled taught and the cantilever is deflected as the ligand-receptor bond is challenged until rupture. The rupture force (RF) and instantaneous loading rate (LR), dF/dt, are extracted from this region of the curve as shown.
(Bv) The ligand is once again free at the end of the cycle. Cartoons of TLR4 in association with myeloid differentiation factor 2 (PDB id: 3FXI) and its ligand lipopolysaccharide (PDB id: 1KGC) were generated using pymol v2.1.1 and used for illustrative purposes only.
Cell Chemical Biology  , DOI: ( /j.chembiol )
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