3D active stabilization for single-molecule imaging.

Area of Science:

• Microscopy
• Biophysics
• Optical Engineering

Background:

• Mechanical drift during imaging degrades super-resolution microscopy resolution and introduces artifacts.
• Accurate correction of sample and setup motion is crucial for high-fidelity super-resolution imaging.

Purpose of the Study:

• To present a protocol for implementing active stabilization to minimize drift in super-resolution microscopy.
• To enable drift correction to approximately 1 nm in all three dimensions.

Main Methods:

• Implementation of a separate illumination and detection path for acquiring fiducial diffraction patterns.
• Real-time focus locking using kHz calculations on a graphics processing unit for nanometer-level focus adjustments.
• Integration with custom and standard microscopy hardware.

Main Results:

• Reduction of drift to ~1 nm across all three dimensions.
• Prevention of movement artifacts in single-molecule and super-resolution images.
• Successful application for extended acquisitions, including multicolor super-resolution.

Conclusions:

• The active stabilization method effectively reduces drift below photon-limited localization precision.
• The protocol is user-friendly, requiring no specialist knowledge and can be implemented in standard biological laboratories within approximately two weeks.
• This approach eliminates the need for complex algorithms or extensive hardware modifications for drift correction.