Simultaneous dual-Raman-shift scanning-free stimulated Raman scattering microscopy for label-free biomolecular...

Area of Science:

• Biomedical Optics
• Chemical Imaging
• Microscopy

Background:

• Conventional stimulated Raman scattering (SRS) microscopy is limited by slow Raman-shift scanning, hindering real-time biological applications.
• Achieving chemical specificity in microscopy often requires time-consuming spectral acquisition.

Purpose of the Study:

• To develop a faster, scanning-free SRS microscopy technique for real-time chemical imaging.
• To enable simultaneous acquisition of multiple molecular vibrational signatures with high specificity.

Main Methods:

• Introduced simultaneous dual-Raman-shift scanning-free SRS (SDRSRS) microscopy.
• Utilized birefringent crystals for controlled optical path differences and orthogonal polarizations.
• Implemented custom dual-channel detection with collinear balanced detection for improved signal-to-noise ratio.

Main Results:

• Achieved over 10-fold faster imaging compared to conventional SRS microscopy.
• Demonstrated simultaneous CH₃ and CH₂ mapping for lipid droplet dynamics in living cells.
• Enabled quantitative distinction of immunotherapy responses in liver cancer models and rapid classification of colorectal cancer.

Conclusions:

• SDRSRS microscopy provides rapid, label-free, chemically specific imaging with dual vibrational contrast.
• The technique is suitable for live metabolic monitoring, clinical pathology, and drug-response studies.
• SDRSRS enhances the applicability of SRS microscopy in dynamic biological and clinical settings.