Diffraction-Unlimited Fluorescence Imaging with an EasySTED Retrofitted Confocal Microscope.

Area of Science:

• Microscopy
• Optical Engineering
• Biotechnology

Background:

• Confocal laser scanning microscopes are widely used but limited by diffraction.
• Commercial stimulated emission depletion (STED) microscopes offer super-resolution but can be expensive.
• Retrofitting existing confocal systems presents an attractive alternative for users seeking enhanced imaging.

Purpose of the Study:

• To introduce the easySTED technology for retrofitting confocal microscopes.
• To enable diffraction-unlimited imaging via STED microscopy on existing platforms.
• To simplify the technical complexity and alignment procedures for STED upgrades.

Main Methods:

• Development of the easySTED principle utilizing a joint beam path for excitation and depletion light.
• Integration of a common laser source (supercontinuum or two lasers via single-mode fiber).
• Minimal modifications to the confocal microscope's beam path, including polarization control and beam splitter adaptation.

Main Results:

• The easySTED design significantly reduces alignment complexity by sharing a common beam path.
• It allows for the feasible use of a single laser source for both excitation and depletion.
• Minor hardware additions enable the transformation of a confocal microscope into a STED system.

Conclusions:

• The easySTED technology offers a practical and cost-effective method to upgrade confocal microscopes to STED systems.
• It simplifies the process of achieving diffraction-unlimited imaging.
• This approach democratizes access to super-resolution microscopy techniques.