Fluorogenic cell surface glycan labelling with fluorescence molecular rotor dyes and nucleic acid stains

Area of Science:

• Biochemistry
• Cell Biology
• Fluorescence Microscopy

Background:

• Sialic acids are crucial cell surface glycans involved in various biological processes.
• Current methods for cell surface imaging often require multiple washing steps, which can be cumbersome and affect cell viability.
• Fluorescence molecular rotors (FMRs) are sensitive to their local environment, offering potential for novel imaging applications.

Purpose of the Study:

• To develop a wash-free method for imaging sialic acids on live cell surfaces.
• To utilize the environmental sensitivity of FMRs for detecting cellular changes.
• To explore the potential of covalent labeling of sialic acids with FMRs for biological studies.

Main Methods:

• Covalent labeling of sialic acids on live cell surfaces and mucin using FMRs (CCVJ, Cy3, thioazole orange).
• Imaging of labeled cells using fluorescence microscopy.
• Dual labeling experiments combining FMRs with environmentally insensitive dyes.

Main Results:

• Covalent labeling of sialic acids with FMRs significantly increased their fluorescence.
• This labeling enabled effective, wash-free imaging of live cell surfaces.
• Dual labeling allowed for the detection of alterations, such as changes in cross-linking.

Conclusions:

• Covalent labeling of sialic acids with FMRs provides a robust and efficient method for live cell surface imaging.
• This approach simplifies cellular imaging protocols by eliminating washing steps.
• The technique holds promise for studying dynamic changes in cell surface structures and functions.