Aberration-accounting calibration for 3D single-molecule localization microscopy.

Area of Science:

• Biophysics
• Microscopy
• Optical Imaging

Background:

• 3D Single-Molecule Localization Microscopy (3D-SMLM) is crucial for visualizing cellular structures at the nanoscale.
• Accurate axial localization is essential for reconstructing 3D molecular distributions but is challenging due to optical aberrations.
• Existing methods often rely on complex computational corrections for aberrations like spherical aberration.

Purpose of the Study:

• To present a straightforward, sample-based calibration technique for axial detection in 3D-SMLM.
• To experimentally determine calibration curves that account for imaging depth and spherical aberration.
• To provide a practical alternative to computational correction methods.

Main Methods:

• Utilized microspheres coated with fluorescent molecules as calibration standards.
• Generated calibration curves based on point spread function (PSF) shaping and intensity measurements across the imaging depth.
• Employed an astigmatic imaging setup to demonstrate the method's efficacy.

Main Results:

• Successfully obtained calibration curves for axial detection using the microsphere standard.
• The method effectively accounts for spherical aberration without the need for computational correction.
• Demonstrated the technique's efficiency within a 1.2 μm range above the coverslip.

Conclusions:

• The proposed sample-based calibration technique offers a simple and effective solution for improving axial localization accuracy in 3D-SMLM.
• This method bypasses the need for computationally intensive aberration correction, making 3D-SMLM more accessible.
• The technique is particularly useful for astigmatic imaging systems and enhances the reliability of 3D reconstructions.