applications of atomic force microscopy in pharmaceutical research

... used for atomic force microscopy Scanning 17 , 11 7 12 1 Imaging Methods in AFM 13 2 Imaging Methods in Atomic Force Microscopy Davide Ricci and Pier Carlo Braga 1 Introduction ... area of the labora- tory free from contaminants for the operations of sample and cantilever mounting. 5.2. Imaging in Liquid One of the main reasons for the success of AFM in biomedical investiga- ... spaced intervals, generally from 64 up to 2048 points per line. The number of lines is usually chosen to be equal to the number of data points per line, obtain- ing at the end a square grid of data

Ngày tải lên: 06/08/2014, 02:20

... (2000) Chemical force microscopy of microcontact-printed self-assembled monolayers by pulsed- force- mode atomic force microscopy. Ultramicroscopy 82, 203–212. Imaging Methods in AFM 23 30. Willemsen, ... measurable radius of curvature of the tip is not in fact involved in the imaging process, but instead smaller local From: Methods in Molecular Biology, vol. 242: Atomic Force Microscopy: Biomedical ... scanner following the manufacturer’s instructions. 3.1. Effects of Intrinsic Nonlinearity If the extension of the scanner in any one direction is plotted as a function of the driving signal, the

Ngày tải lên: 06/08/2014, 02:20

... min). The spe- cific binding signal quickly builds up and remains stable. The interaction is fully revers- ible and can be broken by shifting the equilibrium of the binding reaction by injecting ... coated by using unspecifically interacting proteins (e.g., bovine serum albumin). In protein detection experiments, larger fluctua- tions of the cantilevers are observed (e.g., Fig. 7) than in the ... possible interpretation of this difference might be that it is caused by the proteins absorbing light within the visible spectrum and there- fore inducing some local changes in the index of refraction.

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... Atomic force microscopy investigations into the absorption of cationic polymers Cosmet Toiletr 10 9, 55 – 61 2 Schmitt, R L and Goddard, E D (19 94) Atomic force microscopy II Investigation... ... Calculation of Cuticle Step Heights from AFM Images of Outer Surfaces of Human Hair James R Smith 1 Introduction Atomic force microscopy (AFM) is an ideal technique for noninvasive examination of ... providing a wealth of structural information not always apparent from electron microscopy The fine cuticular structure of human head hair is of interest to those engaged in the... the fields of

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... the recording of pictures with increasing detail. Especially in fluid medium, the investigation of active cells offers numerous facts. As an example of dynamic interactions, a series of images ... (1,2). In contrast with electron microscopy observations in particular, AFM improves biological studies involving imaging by also monitoring dynamic processes. However, the investigation of soft ... results in almost any case in more or less tip contamination. While the shape of the biofouled tip had broadened at the apex in comparison with that of the original 112 Bischoff et al. Fig. 3. Zooming

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... continuously during demineralization in the wet cell of the AFM Thus, each pixel of a line and each line of a scan represent different exposures and offer a continuous record of the demineralization ... the force value of 0.5 nN that corresponds to the Growth Cones by AFM 135 nominal setpoint used during imaging in the case of curve 3, we have an indentation of 950 nm, and for curve we find ... 19 Bischoff, R., Bischoff, G., and Hein, H.-J (2002) Scanning force microscopy (SFM) visualization of adherently growing cells Am Biotech Lab 3, 20–22 20 Bischoff, R., Bischoff, G., and Hoffmann,

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... interest in the application of scanning probe microscopy methods to the imaging... spacing is needed to avoid influence of one indent on the adjacent indent (see discussion in ref 23) Using this ... effect of dehydration leading to the collapse of the demineralized dentin matrix (collagen) was previously mentioned and is of considerable interest from the standpoint of dentin bonding procedures, ... demineralized intertubular dentin as a function of etching time in dilute citric acid for normal dentin. The recession level or time at which a plateau is observed is often useful in describing

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... Atomic force microscopy study of fine structures of the entire surface of red blood cells Scanning Microscopy 9, 9 81 98 8 5 Siedlecki, C A and Marchant, R E ( 19 98 ) Atomic force ... excellent preservation, indistinguishable from that reported in cells of the intact heart. Fig. 5. Electron micrograph detailing the structural complexity of the interior of mammalian ventricular ... putida bacterial biofilms by scanning electron microscopy and both dc... Initially called the scanning force microscope (SFM), it was a development of the previous scanning tunneling microscope

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... of interest. Moreover, correlative informa- tion is obtained and therefore improves the understanding of both microscopies, providing a limit of confidence for AFM imaging of living cells. Finally, ... versa. (D) Increasing the inte- gral gain (see Note 16 during imaging resulted in an artifact-free image and reveal typi- cal jasplakinolide-induced changes, that is, a loss of jasplakinolide A-sensitive ... 21 , 685–696 AFM of Protein Complexes 21 7 16 Atomic Force Microscopy of Protein Complexes Olga I Kiselyova and Igor V Yaminsky 1 Introduction Scanning probe microscopy (SPM) is

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... protein interactions and associations in biological membranes (10). Models of interactions of enzymes with lipid membranes, two-dimensional crystalliza- tion of proteins, the binding kinetics of ... increasing surface packing density driven by increasing lateral pres- sure (11). The inherent changes of packing the lipid in a film undergoing lat- eral phase separation allows for the imaging of ... in bilayers or monolayers, from the polar head- groups in water (11,15). However, protein–lipid interactions, binding, and crystallization processes of the proteins are better imaged in AFM in

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... and incubate the slides at 37°C for 15 s in 0.05% trypsin-solution (Difco). 2. Rinse the slides briefly in PBS and staining and stain the treated slides in 5% Giemsa solution for 8 min. 3. Rinse ... resuspend pellet in 10 mL of hypotonic solution containing 0.075 M KCl. Incubate at 37°C for 15 min (see Note 1). 3. After the incubation add two drops of the ice cold fixative containing methanol/ ... rinsing in deionized water and air drying. 5. Stain the slides in 5% Giemsa solution at room temperature for 45 min, rinse with water, and allow to dry. 3.4. Protein Digestion 1. After washing

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... 3.9.1 Force Mapping A force map is a 2D array of force curves. (You already know a single force curve from the force calibration menu of the BioScope.) In a force curve, the force acting on the AFM ... independent of the loading force and independent of the elastic modulus of the cell. The following section explains the analysis of the data and gives practical hints for data acquisition. 3.9.1 Force ... 64 points in the force curve). When you increase the length of the force curve, the force resolution of the curve will become worse. Smaller lateral pixel numbers permit more points in the force

Ngày tải lên: 06/08/2014, 02:20

... Department of Physics, University of California, Santa Barbara, Santa Barbara, California 9 310 6 Martin Benoit ( 91) , Center for... Scanning Tunneling Microscopy III Atomic Force Microscopy ... University of Virginia School of Medicine, Charlottesville, Virginia 22908 Andreas Engel (257), M E Müller Institute, Biocenter, University of Basel, CH-4056 Basel, Switzerland Ernst-Ludwig Florin (19 ... Microscopy A Combination with Optical Microscopy B Combination with Patch-Clamp Technique IV Force Spectroscopy A Molecular Adhesion B Intramolecular Forces C Combination with Optical

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... pulling, and in this way unfolding events occurring in a single protein can be examined Each peak is attributed to a breakage of a main stabilizing... folded protein structure Recombinant DNA ... observation time. For instance, the off-rate for biotin/avidin binding at room temperature is on the order of 6 months. If a small force of about 80 pN is applied, the binding potential is deformed ... that in these experiments a certain type of interaction between a certain amino acid group within a protein and the metal determines the first contact. The exact nature of the measured adhesion forces

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... spring constant and the sensitivity of [...]... determining the spring constant of cantilevers for scanning force microscopy Rev Sci Instrum 64, 40 3 40 5 Han, W., Lindsay, S M., and Jing, ... Biological applications of the oscillating noncontact mode, which is based on the use of attractive interactions, remain to be established. IV. Requirements for the Imaging of Intact Cells By imaging intact ... properties of molecules at the surface of live cells. These multicapabilities of the AFM will certainly be exploited further in the studies of living cells, bringing our understanding of cellular

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... architecture of the network Prominent examples of actin-binding proteins are α-actinin (bundler), gelsolin (severs filaments, binds to monomers), filamin (cross-links filaments), myosin (slides along ... Typical values of loading forces in the imaging of cells may be between 10 0 pN and 1 nN These forces... determine the elastic properties of soft samples, including cells In addition it ... concentrations In cells, there is a multitude of actin-binding proteins which... parameter settings have an array size of 64∗ 64 force curves, each consisting of 10 0 data points on approach

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... limit of loading force in range of analysis F 2 upper limit of loading force in range of analysis F cone loading force predicted from the Hertz model for a conical indenter F paraboloid loading force ... cantilever (off the surface) d 1 lower limit of deflection in range of analysis d 2 upper limit of deflection in range of analysis E elastic or Young’s modulus of sample F loading force of AFM cantilever ... investigation of the migration of cells. List of Symbols α half-opening angle of conical indenter δ indentation of (soft) sample d deflection of AFM cantilever d 0 zero deflection of the free AFM

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... at a certain critical force (unbinding force) , and the cantilever finally jumps back to the resting position (at z = 21 nm) The quantitative force measure of the unbinding force of a single ligand–receptor ... uncertainty in determining f u values, given Fig Distribution of unbinding forces An empirical probability density function (pdf, solid line) was constructed from about 150 values of unbinding forces ... corresponds to a kinetic offrate of koff = 6.7 10−2 s−1 (Kienberger, Kada et al., 2000) Unbinding Force versus Loading Rate Theoretical studies determined that the unbinding force of specific and

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... VE-cadherin determined by atomic force microscopy. Single Mol. 1, 119–122. 130 Peter Hinterdorfer Fig. 7 Dependence of the unbinding force on the pulling velocity. The unbinding force of the first ... 128 Peter Hinterdorfer Fig. 5 Unbinding force distribution of trans-interacting VE-cadherins. Frequency distribution of unbinding forces between tip- and plate-attached PEG/VE-cadherin-Fc measured ... diffusion, which in turn would result in a reduction of the number of trans-interacting cadherins and finally in junctional dis- sociation. If diffusion of cadherins is restrained by tethering them cytoplasmatically

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... energy- transducing network. Protein packing may play a determining role in the formation of functional photosynthetic domains and membrane curvature. To further investigate in detail the packing effects of ... functionalized invaginations of the intracyto- plasmic membrane containing the photosynthetic machinery. The most abundant protein complexes in the intracytoplasmic membrane are light-harvesting (LH) ... zoomed -in image of the areas indicated by the dashed line in Fig. 1A (area 1). Inset: 3D enhanced close view showing weakly protruding LH2’s (black arrows) in between the strongly protruding zig-zag...

Ngày tải lên: 18/02/2014, 18:20