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Chapter 6 : Atomic Force Microscopy

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Abstract:

The advent of atomic force microscopy (AFM), one technique in a family of new microscopies called scanning probe microscopies, has recently opened a wide range of novel applications for microbiologists. This chapter focuses on the use of AFM in microbiology. Rather than providing an exhaustive review of the literature in this area, the chapter emphasizes methods and gives recommendations for reproducible, reliable experiments. The first section concentrates on sample preparation procedures: selection of appropriate substrates and immobilization protocols available for isolated macromolecules, cell surface layers, and whole cells. The second section deals with the various aspects of AFM imaging: different imaging modes together with common problems and artifacts, imaging parameters, and imaging environments. The third section focuses on AFM force measurements: the principle of force-distance curves and their application to probe molecular interactions and mechanical properties. Finally, isoporous polymer membranes can be used to immobilize large objects such as whole cells. The protocols differ according to the type of sample investigated, i.e., macromolecules, cell surface layers, or whole cells. Probing molecular interactions method has been used to measure the forces between -coated probes and solids of different surface hydrophobicities.

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6

Key Concept Ranking

Atomic Force Microscopy
0.87097013
Scanning Probe Microscopy
0.7308107
Atomic Force Microscope
0.52586883
Electron Microscopy
0.50791246
Bacterial Proteins
0.49717015
0.87097013
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Figures

Image of FIGURE 1
FIGURE 1

General design of an atomic force microscope.

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 2
FIGURE 2

High-resolution AFM image, obtained with the specimen in aqueous solution, of purple membrane adsorbed to freshly cleaved mica ( ). A fully reversible, force-induced conformational change was observed: at the top of the image, the force applied to the atomic force microscope stylus was 100 pN. During scanning of the surface line by line, the force was increased until it reached 150 pN at the bottom of the image. White outlines indicate bacteriorhodopsin trimers. (Reprinted from reference with permission of the publisher.)

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 3
FIGURE 3

Schematic illustration of two immobilization methods for AFM investigation of native, single microbial cells. (A) Agar gel; (B) porous membrane.

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 4
FIGURE 4

AFM height image (range = 750 nm) recorded under water showing cells trapped by a pore of a polycarbonate membrane. By trapping the cells mechanically into a porous membrane, single cells can be imaged under physiological conditions without any pretreatment.

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 5
FIGURE 5

AFM height (A) and deflection (B) images recorded under water for the surfaces of dormant spores of the fungus . The height image (A) together with the vertical cross section (taken along the dashed line) reveal the presence of a heterogeneous outer layer ∼35 nm thick. The deflection image (B) shows that the outer layer is made of rodlet structures 10 ± 1 nm in diameter.

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 6
FIGURE 6

AFM force measurements: different parts of a force-distance curve. Labels indicate the approach (1, 2, 3) and retraction (3, 4, 4′) parts.

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 8
FIGURE 8

Stretching cell surface macromolecules. Typical force-extension curve recorded under water between a silicon nitride probe and the surface of a germinating spore (thin line, starting at 0 mm extension). Elongation forces were well described by an extended freely jointed chain model (thick line, starting at 200 mm extension) with parameters consistent with values reported for the elastic deformation of single dextran and amylose polysaccharides ( ).

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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Image of FIGURE 7
FIGURE 7

Combining AFM imaging and force spectroscopy to unzip proteins from the HPI layer of ( ). (A) Control AFM topograph of the inner surface of the HPI layer. (B) Force-extension curve recorded for this inner surface region showing a saw-tooth pattern with six force peaks of about 300 pN. (C) The same inner surface area imaged after recording of the force curve; a molecular defect the size of a hexameric HPI protein complex has clearly been created. (Reprinted from reference with permission of the publisher.)

Citation: Dufrêne Y. 2007. Atomic Force Microscopy, p 96-107. In Reddy C, Beveridge T, Breznak J, Marzluf G, Schmidt T, Snyder L (ed), Methods for General and Molecular Microbiology, Third Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817497.ch6
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References

/content/book/10.1128/9781555817497.chap6
1. Abu-Lail, N. I.,, and T. A. Camesano. 2002. Elasticity of Pseudomonas putida KT2442 surface polymers probed with single-molecule force microscopy. Langmuir 18:40714081.
2. Ahimou, F.,, F. A. Denis,, A. Touhami,, and Y. F. Dufrêne. 2002. Probing microbial cell surface charges by atomic force microscopy. Langmuir 18:99379941.
3. Ahimou, F.,, A. Touhami,, and Y. F. Dufrêne. 2003. Realtime imaging of the surface topography of living yeast cells by atomic force microscopy. Yeast 20:2530.
4. Amro, N. A.,, L. P. Kotra,, K. Wadu-Mesthrige,, A. Bulychev,, S. Mobashery,, and G.-Y. Liu. 2000. Highresolution atomic force microscopy studies of the Escherichia coli outer membrane: structural basis for permeability. Langmuir 16:27892796.
5. Arnoldi, M.,, C. M. Kacher,, E. Bäuerlein,, M. Radmacher,, and M. Fritz. 1998. Elastic properties of the cell wall of Magnetospirillum gryphiswaldense investigated by atomic force microscopy. Appl. Phys. A 66:S613S617.
6. Beech, I. B.,, C. W. S. Cheung,, D. B. Johnson,, and J. R. Smith. 1996. Comparative studies of bacterial biofilms on steel surfaces using atomic force microscopy and environmental scanning electron microscopy. Biofouling 10:6577.
7. Binnig, G.,, C. F. Quate,, and C. Gerber. 1986. Atomic force microscope. Phys. Rev. Lett. 56:930933.
8. Butt, H.-J. 1992. Measuring local surface charge densities in electrolyte solutions with a scanning force microscope. Biophys. J. 63:578582.
9. Butt, H.-J.,, M. Jaschke,, and W. Ducker. 1995. Measuring surface forces in aqueous electrolyte solution with the atomic force microscope. Bioelectrochem. Bioenerg. 38:191201.
10. Camesano, T. A.,, M. J. Natan,, and B. E. Logan. 2000. Observation of changes in bacterial cell morphology using tapping mode atomic force microscopy. Langmuir 16:45634572.
11. Cappella, B.,, and G. Dietler. 1999. Force-distance curves by atomic force microscopy. Surf. Sci. Rep. 34:1104.
12. Clausen-Schaumann, H.,, M. Seitz,, R. Krautbauer,, and H. E. Gaub. 2000. Force spectroscopy with single biomolecules. Curr. Opin. Chem. Biol. 4:524530.
13. Cleveland, J. P.,, S. Manne,, D. Bocek,, and P. K. Hansma. 1993. A nondestructive method for determining the spring constant of cantilevers for scanning force microscopy. Rev. Sci. Instrum. 64:403405.
14. Colton, R. J.,, A. Engel,, J. E. Frommer,, H. E. Gaub,, A. A. Gewirth,, R. Guckenberger,, J. Rabe,, W. M. Heckel,, and B. Parkinson (ed.). 1998. Procedures in Scanning Probe Microscopies. John Wiley & Sons Ltd., Chichester, England.
15. Crawford, S. A.,, M. J. Higgins,, P. Mulvaney,, and R. Wetherbee. 2001. Nanostructure of the diatom frustule as revealed by atomic force and scanning electron microscopy. J. Phycol. 37:543554.
16. Dufrêne, Y. F. 2000. Direct characterization of the physicochemical properties of fungal spores using functionalized AFM probes. Biophys. J. 78:32863291.
17. Dufrêne, Y. F. 2001. Application of atomic force microscopy to microbial surfaces: from reconstituted cell surface layers to living cells. Micron 32:153165.
18. Dufrêne, Y. F. 2002. Atomic force microscopy, a powerful tool in microbiology. J. Bacteriol. 184:52055213.
19. Dufrêne, Y. F. 2003. Recent progress in the application of atomic force microscopy imaging and force spectroscopy to microbiology. Curr. Opin. Microbiol. 6:317323.
20. Dufrêne, Y. F. 2004. Using nanotechniques to explore microbial surfaces. Nat. Rev. Microbiol. 2:451460.
21. 20a.Dufrêne, Y. F. 2003. Atomic force microscopy provides a new means for looking at microbial cells. ASM News 69:438442.
21. Dufrêne, Y. F.,, C. J. P. Boonaert,, P. A. Gerin,, M. Asther,, and P. G. Rouxhet. 1999. Direct probing of the surface ultrastructure and molecular interactions of dormant and germinating spores of Phanerochaete chrysosporium. J. Bacteriol. 181:53505354.
22. Firtel, M.,, and T. J. Beveridge. 1995. Scanning probe microscopy in microbiology. Micron 26:347362.
23. Fisher, T. E.,, P. E. Marszalek,, and J. M. Fernandez. 2000. Stretching single molecules into novel conformations using the atomic force microscope. Nat. Struct. Biol. 7:719724.
24. Forsythe, J. H.,, P. A. Maurice,, and L. E. Hersman. 1998. Attachment of a Pseudomonas sp. to Fe(III)-(hydr)oxide surfaces. Geomicrobiology 15:293308.
25. Gad, M.,, and A. Ikai. 1995. Method for immobilizing microbial cells on gel surface for dynamic AFM studies. Biophys. J. 69:22262233.
26. Grantham, M. C.,, and P. M. Dove. 1996. Investigation of bacterial-mineral interactions using fluid tapping mode atomic force microscopy. Geochim. Cosmochim. Acta 60:24732480.
27. Hansma, H. G.,, and J. H. Hoh. 1994. Biomolecular imaging with the atomic force microscope. Ann. Rev. Biophys. Biomol. Struct. 23:115139.
28. Hansma, H. G.,, J. Vesenka,, C. Siegerist,, G. Kelderman,, H. Morrett,, R. L. Sinsheimer,, V. Elings,, C. Bustamante,, and P. K. Hansma. 1992. Reproducible imaging and dissection of plasmid DNA under liquid with the atomic force microscope. Science 256:11801184.
29. Hartley, P.,, M. Matsumoto,, and P. Mulvaney. 1998. Determination of the surface potential of two-dimensional crystals of bacteriorhodopsin by AFM. Langmuir 14:52035209.
30. Hinterdorfer, P.,, W. Baumgartner,, H. J. Gruber,, K. Schilcher,, and H. Schindler. 1996. Detection and localization of individual antibody-antigen recognition events by atomic force microscopy. Proc. Natl. Acad. Sci. USA 93:34773481.
31. Holstein, T. W.,, M. Benoit,, G. V. Herder,, G. Wanner,, C. N. David,, and H. E. Gaub. 1994. Fibrous minicollagens in Hydra nematocysts. Science 265:402404.
32. Hörber, J. K. H.,, and M. J. Miles. 2003. Scanning probe evolution in biology. Science 302:10021005.
33. Ikai, A. 1996. STM and AFM of bio/organic molecules and structures. Surf. Sci. Rep. 26:261332.
34. Janshoff, A.,, M. Neitzert,, Y. Oberdörfer,, and H. Fuchs. 2000. Force spectroscopy of molecular systems—single molecule spectroscopy of polymers and biomolecules. Angew. Chem. Int. Ed. 39:32133237.
35. Karrasch, S.,, and A. Engel,. 1998. AFM imaging of HPI layers in buffer solution, p. 433439. In R. J. Colton,, A. Engel,, J. E. Frommer,, H. E. Gaub,, A. A. Gewirth,, R. Guckenberger,, J. Rabe,, W. M. Heckel,, and B. Parkinson (ed.), Procedures in Scanning Probe Microscopies. John Wiley & Sons Ltd., Chichester, England.
36. Karrasch, S.,, R. Hegerl,, J. Hoh,, W. Baumeister,, and A. Engel. 1994. Atomic force microscopy produces faithful high-resolution images of protein surfaces in an aqueous environment. Proc. Natl. Acad. Sci. USA 91:836838.
37. Kasas, S.,, and A. Ikai. 1995. A method for anchoring round shaped cells for atomic force microscope imaging. Biophys. J. 68:16781680.
38. Kirby, A. R.,, A. P. Gunning,, and V. J. Morris. 1996. Imaging polysaccharides by atomic force microscopy. Biopolymers 38:355366.
39. Lee, G. U.,, L. A. Chrisey,, and R. J. Colton. 1994. Direct measurement of the forces between complementary strands of DNA. Science 266:771773.
40. Lister, T. E.,, and P. J. Pinhero. 2001. In vivo atomic force microscopy of surface proteins on Deinococcus radiodurans. Langmuir 17:26242628.
41. Lo, Y. S.,, N. D. Huefner,, W. S. Chan,, P. Dryden,, B. Hagenhoff,, and T. P. Beebe. 1999. Organic and inorganic contamination on commercial AFM cantilevers. Langmuir 15:65226526.
42. Lower, S. K.,, M. F. Hochella,, and T. J. Beveridge. 2001. Bacterial recognition of mineral surfaces: nanoscale interactions between Shewanella and α-FeOOH. Science 292:13601363.
43. Lyubchenko, Y. L.,, A. A. Gall,, L. S. Shlyakhtenko,, R. E. Harrington,, P. I. Oden,, B. L. Jacobs,, and S. M. Lindsay. 1992. Atomic force microscopy imaging of double stranded DNA and RNA. J. Biomol. Struct. Dyn. 9:589606.
44. Magonov, S. N.,, and M.-H. Whangbo (ed.). 1996. Surface Analysis with STM and AFM. VCH, New York, N.Y..
45. Marszalek, P. E.,, A. F. Oberhauser,, Y.-P. Pang,, and J. M. Fernandez. 1998. Polysaccharide elasticity governed by chair-boat transitions of the glucopyranose ring. Nature 396:661664.
46. McIntire, T. M.,, and D. A. Brant. 1997. Imaging of individual biopolymers and supramolecular assemblies using noncontact atomic force microscopy. Biopolymers 42:133146.
47. Möller, C.,, M. Allen,, V. Elings,, A. Engel,, and D. J. Müller. 1999. Tapping mode atomic force microscopy produces faithful high-resolution images of protein surfaces. Biophys. J. 77:11501158.
48. Morris, V. J.,, A. R. Kirby,, and A. P. Gunning (ed.). 1999. Atomic Force Microscopy for Biologists. Imperial College Press, London, England.
49. Müller, D. J.,, and A. Engel. 1999. Voltage and pHinduced channel closure of porin OmpF visualized by atomic force microscopy. J. Mol. Biol. 285:13471351.
50. Müller, D. J.,, G. Büldt,, and A. Engel. 1995. Forceinduced conformational change of bacteriorhodopsin. J. Mol. Biol. 249:239243.
51. Müller, D. J.,, W. Baumeister,, and A. Engel. 1996. Conformational change of the hexagonally packed intermediate layer of Deinococcus radiodurans monitored by atomic force microscopy. J. Bacteriol. 178:30253030.
52. Müller, D. J.,, M. Amrein,, and A. Engel. 1997. Adsorption of biological molecules to a solid support for scanning probe microscopy. J. Struct. Biol. 119:172188.
53. Müller, D. J.,, A. Engel,, and M. Amrein. 1997. Preparation techniques for the observation of native biological systems with the atomic force microscope. Biosens. Bioelectron. 12:867877.
54. Müller, D. J.,, G. Büldt,, and A. Engel,. 1998. Preparation and observation of purple membranes by AFM, p. 425428. In R. J. Colton,, A. Engel,, J. E. Frommer,, H. E. Gaub,, A. A. Gewirth,, R. Guckenberger,, J. Rabe,, W. M. Heckel,, and B. Parkinson (ed.), Procedures in Scanning Probe Microscopies. John Wiley & Sons Ltd., Chichester, England.
55. Müller, D. J.,, D. Fotiadis,, S. Scheuring,, S. A. Müller,, and A. Engel. 1999. Electrostatically balanced subnanometer imaging of biological specimens by atomic force microscope. Biophys. J. 76:11011111.
56. Müller, D. J.,, W. Baumeister,, and A. Engel. 1999. Controlled unzipping of a bacterial surface layer with atomic force microscopy. Proc. Natl. Acad. Sci. USA 96:1317013174.
57. Müller, D. J.,, J. B. Heymann,, F. Oesterhelt,, C. Möller,, H. Gaub,, G. Büldt,, and A. Engel. 2000. Atomic force microscopy of native purple membrane. Biochim. Biophys. Acta 1460:2738.
58. Ong, Y.-L.,, A. Razatos,, G. Georgiou,, and M. M. Sharma. 1999. Adhesion forces between E. coli bacteria and biomaterial surfaces. Langmuir 15:27192725.
59. Patel, N.,, M. C. Davies,, M. Hartshorne,, R. J. Heaton,, C. J. Roberts,, S. J. B. Tendler,, and P. M. Williams. 1997. Immobilization of protein molecules onto homogeneous and mixed carboxylate-terminated self-assembled monolayers. Langmuir 13:64856490.
60. Pum, D.,, M. Weinhandl,, C. Hödl,, and U. B. Sleytr. 1993. Large-scale recrystallization of the S-layer of Bacillus coagulans E38-66 at the air/water interface and on lipid films. J. Bacteriol. 175:27622766.
61. Razatos, A.,, Y.-L. Ong,, M. M. Sharma,, and G. Georgiou. 1998. Molecular determinants of bacterial adhesion monitored by atomic force microscopy. Proc. Natl. Acad. Sci. USA 95:1105911064.
62. Rief, M.,, F. Oesterhelt,, B. Heymann,, and H. E. Gaub. 1997. Single molecule force spectroscopy on polysaccharides by atomic force microscopy. Science 275:12951297.
63. Schabert, F. A., 1998. Imaging of reconstituted OmpF porin in solution using AFM, p. 429432. In R. J. Colton,, A. Engel,, J. E. Frommer,, H. E. Gaub,, A. A. Gewirth,, R. Guckenberger,, J. Rabe,, W. M. Heckel,, and B. Parkinson (ed.), Procedures in Scanning Probe Microscopies. John Wiley & Sons Ltd., Chichester, England.
64. Schabert, F. A.,, C. Henn,, and A. Engel. 1995. Native Escherichia coli OmpF porin surfaces probed by atomic force microscopy. Science 268:9294.
65. Scheuring, S.,, P. Ringler,, M. Borgnia,, H. Stahlberg,, D. J. Müller,, P. Agre,, and A. Engel. 1999. High resolution AFM topographs of the Escherichia coli water channel aquaporin Z. EMBO J. 18:49814987.
66. Shao, Z.,, J. Mou,, D. M. Czajkowsky,, J. Yang,, and J.-Y. Yuan. 1996. Biological atomic force microscopy: what is achieved and what is needed. Adv. Phys. 45:186.
67. Tortonese, M.,, and M. Kirk. 1997. Characterization of application specific probes for SPMs. SPIE 3009:5360.
68. Touhami, A.,, B. Nysten,, and Y. F. Dufrêne. 2003. Nanoscale mapping of the elasticity of microbial cells by atomic force microscopy. Langmuir 19:45394543.
69. Touhami, A.,, B. Hoffmann,, A. Vasella,, F. A. Denis,, and Y. F. Dufrêne. 2003. Aggregation of yeast cells: direct measurement of discrete lectin-carbohydrate interactions. Microbiol. SGM 149:28732878.
70. Touhami, A.,, M. Jericho,, and T. J. Beveridge. 2004. Atomic force microscopy of cell growth and division in Staphylococcus aureus. J. Bacteriol. 186:32863295.
71. van der Aa, B. C.,, R. M. Michel,, M. Asther,, M. T. Zamora,, P. G. Rouxhet,, and Y. F. Dufrêne. 2001. Stretching cell surface macromolecules by atomic force microscopy. Langmuir 17:31163119.
72. van der Mei, H. C.,, H. J. Busscher,, R. Bos,, J. de Vries,, C. J. P. Boonaert,, and Y. F. Dufrêne. 2000. Direct probing by atomic force microscopy of the cell surface softness of a fibrillated and non-fibrillated oral streptococcal strain. Biophys. J. 78:26682674.
73. Wagner, P.,, M. Hegner,, P. Kernen,, F. Zaugg,, and G. Semenza. 1996. Covalent immobilization of native biomolecules onto Au(111) via N-hydroxysuccinimide ester functionalized self-assembled monolayers for scanning probe microscopy. Biophys. J. 70:20522066.
74. Weisenhorn, A. L.,, M. Khorsandi,, S. Kasas,, V. Gotzos,, and H.-J. Butt. 1993. Deformation and height anomaly of soft surfaces studied with an AFM. Nanotechnology 4:106113.
75. Wetzer, B.,, D. Pum,, and U. B. Sleytr. 1997. S-layer stabilized solid supported lipid bilayers. J. Struct. Biol. 119:123128.
76. Wilson, D. L.,, K. S. Kump,, S. J. Eppell,, and R. E. Marchant. 1995. Morphological restoration of atomic force microscopy images. Langmuir 11:265272.
77. Xu, W.,, P. J. Mulhern,, B. L. Blackford,, M. H. Jericho,, M. Firtel,, and T. J. Beveridge. 1996. Modeling and measuring the elastic properties of an archaeal surface, the sheath of Methanospirillum hungatei, and the implication for methane production. J. Bacteriol. 178:31063112.
78. Yao, X.,, M. Jericho,, D. Pink,, and T. Beveridge. 1999. Thickness and elasticity of gram-negative murein sacculi measured by atomic force microscopy. J. Bacteriol. 181:68656875.

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