Scanning ion conductance microscopy for imaging biological samples in liquid: a comparative study with atomic force...

Area of Science:

• Biophysics
• Nanotechnology
• Cell Biology

Background:

• Accurate imaging of biological samples at nanoscale resolution is crucial for understanding cellular structures and functions.
• Existing techniques like Atomic Force Microscopy (AFM) have limitations in imaging delicate or steep-sloped samples under physiological conditions.

Purpose of the Study:

• To demonstrate the versatility and applicability of Scanning Ion Conductance Microscopy (SICM) for imaging various biological specimens.
• To highlight the advantages of the approach-retract scanning (ARS)/hopping mode of SICM for high-resolution imaging.

Main Methods:

• Utilized SICM in ARS/hopping mode to image collagen fibrils, chromosomes, fixed and live HeLa cells, and tracheal surfaces.
• Compared SICM imaging results with those obtained from Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM).

Main Results:

• SICM achieved nanoscale resolution imaging of collagen fibrils and chromosomes with steep slopes.
• Successfully visualized delicate cellular projections on fixed HeLa cells and morphological dynamics of live HeLa cells.
• Imaged ciliated and non-ciliated cells on the tracheal surface, with results comparable to SEM.
• ARS/hopping SICM mode provided contact-free imaging of complex biological samples in aqueous environments.

Conclusions:

• SICM, particularly with the ARS/hopping mode, is a powerful technique for high-resolution, 3D topographical imaging of diverse biological samples.
• This method is suitable for studying live cells and unfixed or fixed soft samples with intricate shapes under physiologically relevant conditions.
• SICM offers unique capabilities for biological research where non-contact imaging is essential.