Faster high-speed atomic force microscopy for imaging of biomolecular processes

Area of Science:

• Biophysics
• Nanotechnology
• Microscopy

Background:

• High-speed atomic force microscopy (HS-AFM) allows real-time observation of molecular dynamics, but current speeds (1-12.5 fps) limit the study of many fast biological processes.
• Existing limitations in HS-AFM speed are primarily due to the physical constraints of imaging components, making further significant speed increases challenging.

Purpose of the Study:

• To develop an alternative method for enhancing HS-AFM imaging rates without solely relying on optimizing hardware response times.
• To reduce feedback control errors in HS-AFM to enable faster and less disturbing imaging of dynamic molecular events.

Main Methods:

• Proposed an alternative method to decrease feedback control error in HS-AFM systems.
• This method requires minor software and hardware modifications, making it adaptable to existing HS-AFM instruments.
• Demonstrated the method's efficacy by imaging fragile biomolecules and dynamic processes.

Main Results:

• Achieved faster and less disturbing imaging capabilities with the proposed method.
• Successfully imaged fragile actin filaments and microtubules at near video rates.
• Observed actin polymerization, driven by weak intermolecular interactions, at approximately 8 frames per second.

Conclusions:

• The proposed method offers a viable approach to significantly increase HS-AFM imaging rates.
• This technique enhances the observation of dynamic molecular processes, including those involving weak interactions.
• The adaptability and effectiveness of this method promise broader applications in molecular dynamics studies.