Observation of living cells using the atomic force microscope

Kasas, Sandor; Gotzos, V.; Celio, Marco R.

doi:10.1016/s0006-3495(93)81396-1

Cited by 83 publications

(43 citation statements)

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“…Heinrich Rohrer e Gerd Binnig desenvolveram os procedimentos de controle da corrente de tunelamento que permitiram a construção do primeiro microscópio da família de varredura por sonda mecânica. 6,19 O microscópio de força atômica é um microscópio de varredura por sonda desenhado para a pesquisa de superfícies, que permite superar as limitações da microscopia óptica e caracterizar quantitativamente a superfície celular em condições próximas das fisiológicas, numa escala de resolução até então inacessível. 1,19,26 O princípio de funcionamento da AFM pode ser resumido da seguinte maneira: uma sonda mecânica é montada sobre a extremidade livre de um cantilever e colocada em contato com a superfície da amostra a ser investigada.…”

Section: Discussionunclassified

“…6,19 O microscópio de força atômica é um microscópio de varredura por sonda desenhado para a pesquisa de superfícies, que permite superar as limitações da microscopia óptica e caracterizar quantitativamente a superfície celular em condições próximas das fisiológicas, numa escala de resolução até então inacessível. 1,19,26 O princípio de funcionamento da AFM pode ser resumido da seguinte maneira: uma sonda mecânica é montada sobre a extremidade livre de um cantilever e colocada em contato com a superfície da amostra a ser investigada. O contato dá origem a uma interação altamente localizada entre a sonda e a amostra, o que produz a deflexão do cantilever, enquanto um estágio de varredura (scanner piezelétrico) provê a movimentação lateral da amostra em relação à sonda, descrevendo um padrão de varredura.…”

Section: Discussionunclassified

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2009

Arq Bras Neurocir

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2009

Arq Bras Neurocir

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“…A considerable number of investigators have therefore applied AFM to the observation of organic monolayers and bilayers Weisenhorn et al, 1990;Singh & Keller, 1991), ribonucleic and deoxyribonucleic acid (Thundat et al, 1992(Thundat et al, , 1993Hansma et al, 1992Hansma et al, , 1993bYang et al, 1992), amino acid crystals and proteins (Gould et al, 1988;Drake et al, 1989;Arakawa et al, 1992). There are also several reports on AFM observation of viruses, phages and in vitro cells (Butt et al, 1990;Gould et al, 1990;Henderson et al, 1992;Ikai et al, 1993;Kasas et al, 1993;Parpura et al, 1993). However, AFM studies on cells and tissues in situ have been limited in number, owing to technical difficulties in preparing adequate specimens.…”

Section: Discussionmentioning

confidence: 99%

X‐ray microscopy and imaging of Escherichia coli, LPS and DNA

Rajyaguru

Kado

Torres

et al. 1997

Journal of Microscopy

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SummaryUltrastructural examination by transmission and scanning electron microscopy involves a series of specialized preparation steps which may introduce artefacts in the micrographs. X-ray microscopy can take instant images of specimens but is mostly restricted to a few synchrotron X-ray sources. We have utilized a bench-top nanosecond laserplasma to produce a single-shot source of nanosecond X-rays tuned for maximum contrast with carbon-rich material. To examine the ultrastructure by absorption profiles, we utilized a laser-produced plasma generated by a single-shot laser (1 . 06 mm wavelength, 5 × 10 12 W cm ¹2 intensity) focused on to a silicon target as an X-ray source for high-resolution X-ray microscopy. This approach eliminates the specimen preparation steps. Whole hydrated cells of Escherichia coli and purified preparations of lipopolysaccharide (LPS) and chromosomal DNA (cDNA) were streaked onto poly(methyl methacrylate) (PMMA)-coated grids (resist). This resist was exposed to X-rays under vacuum at a distance of 2 . 5 cm from the target disc. The silicon plasma produced by a 10-ns burst of laser energy (at 20 J) radiates strong emission lines in the region of 300 eV. The X-rays penetrate the sample and their absorption profile is transferred on to the resist where PMMA acts as a negative to generate an image. By atomic force microscopy imaging of this photoresist we have visualized layers around cells of E. coli, darker areas inside the cell probably corresponding to cDNA, and preliminary images of LPS and DNA molecules. This technique has resolution at the 100 Å level, produces images similar to the space-filling models of macromolecules and may be of great value in the study of the ultrastructure of hydrated live biological specimens.

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“…Up to now, it has made the most profound impression on molecular biology where it has been applied to visualizing DNA molecules, and the proteins that act upon nucleic acids (Bustamante andKeller 1995, Zuber andBarklis 2000). It has also been applied, with more limited success, to living and fixed cells (Butt et al 1990, Henderson 1994, Hok 1992, Kasas 1993, Kuznetsov 1997. Another important application has been the study of the growth mechanisms and growth kinetics of protein and virus crystals essential to the technique of x-ray crystallography of biological macromolecules (Kuznetsov et al 1997Malkin et al 1995Malkin et al , 1996McPherson et al 2000.…”

Section: Introductionmentioning

confidence: 99%

Atomic force microscopy imaging of retroviruses: Human immunodeficiency virus and murine leukemia virus

et al. 2004

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Summary:Retroviruses are membrane-enveloped, RNAcontaining viruses that produce a wide range of threatening diseases in higher animals. Among these are human immunodeficiency virus (HIV), which produces acquired immune deficiency syndrome (AIDS) in humans, and murine leukemia virus (MuLV), which produces leukemias in rodents. We have obtained the first atomic force microscopy (AFM) images of these two retroviruses, both isolated from culture media and emerging from infected cell surfaces. The HIV virions are 127 nm diameter on average, and those of MuLV are 145 nm, although there are wide distributions about the means. The AFM images show the arrangement of the envelope protein, responsible for host cell entry, on the surfaces of both virions. Disruption of the viruses using detergents or physical means allowed us to visualize interior structures, including the outer shells of both MuLV and HIV, the cores of MuLV, and the nucleic acid of HIV complexed with core proteins. Using immunolabeling techniques borrowed from electron microscopy, we were able to demonstrate the binding of gold-labeled antibodies directed against the envelope protein of MuLV. The AFM images are revealing, not only in terms of surface topology, but in terms of interior features as well, and they reveal the eccentricities and uniqueness of individual virus particles rather than yielding the average member of the population. Further application of AFM to viruses associated with other pathologies may ultimately have a significant impact on the diagnosis and treatment of virus-promoted diseases.

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Observation of living cells using the atomic force microscope

Cited by 83 publications

References 11 publications

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X‐ray microscopy and imaging of Escherichia coli, LPS and DNA

Atomic force microscopy imaging of retroviruses: Human immunodeficiency virus and murine leukemia virus

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