Single-molecule localization microscopy at 2.4-fold resolution improvement with optical lattice pattern illumination

Area of Science:

• Microscopy
• Biophysics
• Optical Physics

Background:

• Single-molecule localization microscopy (SMLM) offers high resolution but is limited by signal-to-noise ratio (SNR).
• Achieving resolutions below 5 nm in SMLM remains a challenge.
• Optical lattices provide high contrast and penetration depth, potentially improving microscope performance.

Purpose of the Study:

• To introduce LatticeFLUX, a novel SMLM method using wide-field optical lattice illumination.
• To enhance single-molecule excitation and localization precision.
• To overcome the resolution limitations of traditional SMLM.

Main Methods:

• Utilized wide-field optical lattice pattern illumination for single-molecule excitation and localization.
• Calculated Cramér-Rao lower bound to assess resolution enhancement.
• Developed image reconstruction software based on experimental single-molecule fluorescence SNR.
• Employed a 9-frame localization scheme to address uneven illumination.

Main Results:

• LatticeFLUX demonstrated a 2.4-fold improvement in single-molecule localization precision compared to traditional SMLM.
• Verified resolution enhancement capabilities on simulated DNA origami, line pairs, and cytoskeleton structures.
• Confirmed the feasibility of 2D structured light illumination for high precision and throughput.

Conclusions:

• LatticeFLUX significantly improves single-molecule localization precision.
• The method validates the use of structured light illumination for advanced SMLM.
• Paves the way for ultra-high resolution 3D structured-light-illuminated SMLM.