Four-color fluorescence cross-correlation spectroscopy with one laser and one camera

Area of Science:

• Biophysics
• Cell Biology
• Spectroscopy

Background:

• Phospholipid and membrane protein dynamics are crucial for cellular processes.
• Fluorescence cross-correlation spectroscopy (FCCS) is vital for studying molecular interactions at low concentrations.

Approach:

• Developed a novel, economical method using a super-continuum laser and spectral deconvolution for simultaneous multi-color FCCS.
• Utilized customizable excitation wavelengths and spectral fitting to analyze up to four spectrally overlapping fluorophores from a single detector.
• Applied the four-color FCCS technique to polystyrene nanoparticles, lipid vesicles, and membrane-bound molecules.

Key Points:

• Enabled simultaneous measurement of diffusion rates and binding partners for up to four fluorophores.
• Demonstrated the method's capability by observing induced aggregation of nanobeads and lipid vesicles with increasing buffer salinity.
• The technique allows for detailed analysis of complex homo- and heterooligomerization.

Conclusions:

• This cost-effective, adaptable four-color FCCS method offers broad applications for studying molecular interactions in various systems.
• Provides a powerful tool for investigating complex molecular dynamics and oligomerization in both model and living systems.
• Facilitates a deeper understanding of fundamental cellular processes involving diffusion and molecular assembly.