Phase imaging of moving DNA molecules and DNA molecules replicated in the atomic force microscope

Argaman, Miriam; Golan, Roxana; Thomson, Neil H.; Hansma, Helen G.

doi:10.1093/nar/25.21.4379

Cited by 90 publications

(62 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phase imaging is sensitive to differences in material properties like sample viscoelasticity or hydrophobicity, and is a complementary contrast mode yielding more detail than can be observed in height images [17].…”

Section: B Twisted Versus Segmented α-Synuclein Fibril Morphologymentioning

confidence: 99%

Quantitative Characterization of Protein Nanostructures Using Atomic Force Microscopy

Segers-Nolten

Werf

Raaij

et al. 2007

2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society

View full text Add to dashboard Cite

Abstract-The aggregation of proteins into fibrillar structures called amyloid is a characteristic of many diseases, including several neurodegenerative disorders. Although amyloid formation is inherent to several serious diseases, the mechanism of fibril formation and the modes of toxicity are not yet known. High concentrations of fibrillar aggregates of α-synuclein protein are found in the brains of patients suffering from Parkinson's disease. We exploit different contrast modes of high resolution atomic force microscopy (AFM) on fibrils formed by the wild-type α-synuclein protein, and by the familial disease-related A30P, E46K and A53T variants, to get more insight into the in vitro process of fibril assembly. From quantitative analysis of height images measured in tapping mode AFM, we obtained data that are compatible with a twisted hierarchical assembly model [1] for all protein variants. The E46K mutant displays the most distinct and smallest periodicity. The modulation depth for all mutants is very similar, and is smaller for wild-type protein commensurate with the lower fibril height. The detailed morphology observed in phase images indicates however that fibrils may also be formed through the association of fibril segments. To study the mechanical properties of fibrils we applied force while scanning in contact mode, resulting in characteristic deformation of protein fibrils with a periodicity corresponding to the modulation observed in tapping mode. Our observations suggest that the hierarchical assembly model may not be the exclusive mechanism of α-synuclein fibril assembly, but that multiple modes of fibril assembly play a role in α-synuclein fibril formation.

show abstract

Section: B Twisted Versus Segmented α-Synuclein Fibril Morphologymentioning

confidence: 99%

Quantitative Characterization of Protein Nanostructures Using Atomic Force Microscopy

Segers-Nolten

Werf

Raaij

et al. 2007

2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society

View full text Add to dashboard Cite

show abstract

“…Thread like structures in the SPM images in Fig. 1(a) are typical of the samples based on mica substrates with DNA on it (see, e. g., [19,27,28]). Considering the influence of tip diameter on the dimensions in horizontal axis, thickness of the threads approximately represents diameter of the thread like DNA structures and is equal to about 7-8 nm.…”

Section: Structural Studiesmentioning

confidence: 93%

“…The images of the surfaces were obtained by SPM D3100 / Nanoscope IVa (Veeco, Digital Instruments). Standard contact and non-contact modes were used for description of topography and more sophisticated features of the sample surfaces [17][18][19]. Combined modes were used for mapping the electrical and mechanical properties of the hybrid structures during one scan.…”

Section: Methods and Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

Scanning probe microscopic and optical detection of DNA integration within multicomponent structures on Si surfaces

Bukauskas¹

2008

Lithuanian J. Phys.

View full text Add to dashboard Cite

Self-arrangement of DNA based structures on clean mica and modified Si surfaces is investigated by means of scanning probe microscope (SPM) and spectroscopic ellipsometry (SE) method. DNA strands are deposited from a colloidal solution on solid surfaces at room temperature. Surfaces of solid substrates and biomolecular structures are additionally modified by Ag nanoparticles. The self-arranged surface structures are visualized by SPM. The effect of the multicomponent structures on the optical response of complex hybrid structures is studied. Changes in the optical response of the hybrid samples are related to the contributions of self-assembled DNA-based structures and Ag nanoparticles on the Si surfaces. Binding of Ag nanoparticles to the DNA strands and formation of well-ordered structures on the surfaces with DNA are discussed.

show abstract

“…AFM has been used extensively to obtain nanometer scale images of biosystems including proteins, lipid membranes, DNA and cells, generally utilizing ultrasmooth model surfaces such as muscovite mica, highly oriented pyrolytic graphite or self assembled monolayers (Argaman, et al, 1997, Radmacher, 1997, Marchant, et al, 2002, Osada, et al, 2003, Touhami, et al, 2003, Hussain, et al, 2005, Toscano and Santore, 2006. The low surface roughness of these model surfaces is ideal to characterize nanoscale protein features, including specific domains and conformational changes in these proteins upon adsorption.…”

Section: Introductionmentioning

confidence: 99%

Immunological identification of fibrinogen in dual-component protein films by AFM imaging

Soman

Rice

Siedlecki

2008

Micron

View full text Add to dashboard Cite

The success of long-term blood-contacting implanted devices is largely dependent upon the interaction of the blood components with the device biomaterial surface. The ability to study these interactions has been hindered by a lack of methods to measure single-molecule interactions in complex multi-protein environments similar to the environment found in-vivo. In this paper, we demonstrate the use of atomic force microscopy (AFM) in conjunction with gold nanolabels to detect the protein fibrinogen under aqueous conditions without the topographical clues usually necessary for high resolution visualization. BSA was patterned onto both muscovite mica and plasma-treated polydimethylsiloxane (PDMS) substrates and these test substrates were subsequently backfilled with fibrinogen to yield a featureless protein layer. The fibrinogen in this dual protein layer was detected using high resolution AFM imaging following infusion of anti-fibrinogen conjugated with nanogold particles. This AFM immuno-detection technique will potentially be applicable to complex multicomponent protein films adsorbed on clinically-relevant polymers used in medical devices.

show abstract

Phase imaging of moving DNA molecules and DNA molecules replicated in the atomic force microscope

Cited by 90 publications

References 27 publications

Quantitative Characterization of Protein Nanostructures Using Atomic Force Microscopy

Quantitative Characterization of Protein Nanostructures Using Atomic Force Microscopy

Scanning probe microscopic and optical detection of DNA integration within multicomponent structures on Si surfaces

Immunological identification of fibrinogen in dual-component protein films by AFM imaging

Contact Info

Product

Resources

About