High‐resolution imaging and nano‐manipulation of biological structures on surface

Abstract

In this mini-review we discuss our recent findings on imaging and manipulation of biological macromolecular structures by atomic force microscopy (AFM). In the first part of this review, we focus on high-resolution imaging of selected biological samples. AFM images of membrane proteins have revealed detailed conformational features related to identifiable biological functions. Different self-assembling behaviors of short peptides into supramolecular structures on various substrates under controlled environmental conditions have been systematically studied with AFM imaging. In the second part, we present a novel nano-manipulation technique for manipulating, isolating, amplifying, and sequencing of individual DNA molecules, which may find unique applications in the analysis of difficult sequence structures. Finally, we discuss how to characterize the elasticity of individual biomolecules and live cells. These results demonstrate that not only the high resolution capacity of the AFM is suited to resolve certain biological questions, but can also be applied to single molecule isolation and biomechanical analysis with its unique advantages.

Scanning ion conductance microscopy for imaging biological samples in liquid: A comparative study with atomic force microscopy and scanning electron microscopy

“…Furthermore, recent advances in AFM have enabled high-speed imaging of soft samples (Picco et al, 2008(Picco et al, , 2007Ando et al, 2001), allowing the direct visualization of biomolecules and their movement in liquid conditions (Uchihashi and Ando, 2011;Kodera et al, 2010). However, it has remained difficult to image the nanoscale topography of larger meso-and microscale biological samples by AFM, because there may be artifacts due to the force between the tip and sample, as well as other factors such as tip geometry and lateral forces (Zhang et al, 2011;Braet et al, 2001).…”

Mapping Membrane Topology Label Free and Corrected for Changes in the Refractive Index of the Membrane on a Nanometer Scale

“…a cell surface by scanning a sharp tip over the cell. In AFM, the interaction between the specimen and the tip is measured by the deflection of the cantilever (the tip holder) (Zhang et al, 2010). A topographic map of the cellular membrane can be created using AFM (Duman et al, 2010).…”

Facilitating the pickup of individual DNA molecules by AFM nanomanipulation with tips mechanically worn on bare mica

“…Our group reported a method to isolate individual DNA with AFM tips, which is potentially useful for DNA sequencing and direct molecular haplotyping of genomic DNA Lu et al, 2004;Zhang et al, 2007). However, the pickup efficiency is not high enough due to the complicated and uncontrollable interactions between the AFM tips and the nano-objects (Requicha et al, 2001;Zhang et al, 2011).…”