Patterned illumination single molecule localization microscopy (piSMLM): user defined blinking regions of interest

Area of Science:

• Biophysics
• Microscopy
• Optical Engineering

Background:

• Single molecule localization microscopy (SMLM) offers nanoscale resolution but suffers from image artifacts due to uneven illumination.
• Gaussian beam illumination in SMLM leads to insufficient light intensity at the periphery, degrading reconstructed image quality.

Purpose of the Study:

• To develop a patterned illumination SMLM (piSMLM) system for uniform and high-irradiance sample illumination.
• To overcome the limitations of conventional SMLM illumination for improved super-resolution imaging.

Main Methods:

• Utilized computer-generated holography with a phase-only spatial light modulator (SLM) and a modified Gerchberg-Saxton algorithm.
• Generated user-defined, homogeneous, and nearly speckle-free illumination patterns.
• Demonstrated piSMLM using fluctuation binding-activated localization microscopy (fBALM) to image nuclear structures.

Main Results:

• Achieved irradiance of 1-5 kW/cm² with a 200 mW laser over areas of 2000-500 µm², and up to 20 kW/cm² by reducing the region of interest.
• Successfully obtained super-resolution fBALM images of nuclear structures at the nanometer scale.
• piSMLM effectively minimized illumination-induced artifacts, enhancing image quality.

Conclusions:

• piSMLM provides a robust solution for uniform and high-irradiance illumination in SMLM.
• The developed technique significantly improves super-resolution imaging capabilities for subcellular structures.
• This advancement enables more detailed visualization of nanoscale biological organization.