Combined Labelled and Label-free SERS Probes for Triplex Three-dimensional Cellular Imaging

Area of Science:

• Cellular and Molecular Biology
• Spectroscopy
• Biomedical Imaging

Background:

• Cells are intricate chemical systems where molecular composition and interactions dictate biological function.
• In-situ, non-destructive characterization of complex cellular processes is crucial for understanding cell biology.
• Existing imaging techniques face limitations in simultaneously visualizing multiple cellular components and molecules without labels.

Purpose of the Study:

• To develop and demonstrate a novel multiplex 3D Surface-Enhanced Raman Spectroscopy (SERS) imaging technique.
• To achieve simultaneous, non-destructive, and label-free/labeled imaging of cellular organelles and molecules in live cells.
• To investigate time-dependent changes in cell nuclei and membrane receptors during apoptosis.

Main Methods:

• Simultaneous 3D imaging of nucleus and membrane in single HeLa cells using Surface-Enhanced Raman Spectroscopy (SERS).
• Application of both labeled and label-free SERS for comprehensive chemical characterization.
• Utilizing highly confocal conditions for precise molecular localization (folate, LHRH) and stereoscopic description.
• Employing statistical multivariate methods for analyzing time-dependent cellular changes during apoptosis.

Main Results:

• Demonstrated simultaneous 3D imaging of nucleus and membrane in live HeLa cells.
• Achieved precise localization of folate and LHRH on the cell membrane using SERS.
• Successfully analyzed time-dependent chemical changes in cell nuclei and membrane receptors during apoptosis.
• Showcased the capability of SERS for both temporal and spatial live-cell imaging.

Conclusions:

• Multiplex 3D SERS imaging offers a powerful, non-destructive method for live-cell analysis at the subcellular level.
• This technique overcomes limitations of fluorescence microscopy by enabling simultaneous labeled and label-free imaging.
• It provides a new and attractive 2D/3D tracing method for biomedical research, particularly for studying dynamic cellular processes like apoptosis.