The first observation of double-stranded DNA by atomic force microscopy in the late 1980’s greatly encouraged many biological researchers to jump into the nanoworld. Here we briefly review the history of how AFM has been utilized to reveal nanometer-scale structures of DNA-protein complexes, and we highlight key technical developments that have accelerated applications of AFM to molecular biolo...

We have designed and developed a combined system of pulsed laser deposition (PLD) and non-contact atomic force microscopy (NC-AFM) for observations of insulator metal oxide surfaces. With this system, the long-period iterations of sputtering and annealing used in conventional methods for preparing a metal oxide film surface are not required. The performance of the combined system is demonstrate...

The atomic force microscope (AFM) was used to image supercooled plasm id DNA deposited on a mica surface in either a foydrated or desiccated state. Hydrated plasmid was precisely cut by the scanning tip at a location determined by the instrument operator. Small pieces of ON A (100-150 mm in length) were excised and deposited adjacent to the dissected plasmid, demonstrating that it is possible t...

Atomic force microscopy (AFM) has been used to image a variety of virus particles in vitro and could, conceivably, be used as a useful diagnostic for their presence, their structural characterization and even their identification. Virus particles can be imaged by AFM in air, under alcohol or in physiological medium, and accurate measurements of their dimensions obtained. In addition, the appear...

Recent development of atomic force microscopy (AFM) applications in imaging living cells is reviewed, focusing on technical progress and application advancements made in the following major areas: (i) high-resolution imaging of cellular structures, (ii) real-time monitoring of cellular dynamic processes, and (iii) detecting micromechanical properties of the cell. Technical and experimental diff...

Quantifying the tip-sample interaction forces in amplitude-modulated atomic force microscopy (AM-AFM) has been an elusive yet important goal in nanoscale imaging, manipulation and spectroscopy using the AFM. In this paper we present a general theory for the reconstruction of tip-sample interaction forces using integral equations for AM-AFM and Chebyshev polynomial expansions. This allows us to ...

Since the late 1980s, atomic force microscopy (AFM) has been increasingly used in biological sciences and it is now established as a versatile tool to address the structure, properties and functions of biological specimens. AFM is unique in that it provides three-dimensional images of biological structures, including biomolecules, lipid films, 2D protein crystals and cells, under physiological ...

The accuracy of topography imaging in contact force mode of atomic force microscopy (AFM) depends on the one-to-one corresponding relationship between the cantilever deflection and the tip-sample distance, whereas such a relationship cannot be always achieved in the presence of friction and incline angle of sample surface. Recently, we have developed a novel operation mode in which we keep the ...

The mechanism of DNA transfer from Escherichia coli (E. coli) Hfr donor strain AT2453 to recipient strain AB1157 during the conjugation process has been investigated by liquid atomic force microscopy (AFM). With the success of immobilizing both E. coli strains on gelatin-treated glass under aqueous solution, the F-pilus between an E. coli mating pair could be clearly imaged and dissected by an ...

Microbial cells sense and respond to their environment using their surface constituents. Therefore, understanding the assembly and biophysical properties of cell surface molecules is an important research topic. With its ability to observe living microbial cells at nanometer resolution and to manipulate single-cell surface molecules, atomic force microscopy (AFM) has emerged as a powerful tool ...