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

Area of Science:

• Biophysics
• Spectroscopy
• Cell Biology

Background:

• Molecular diffusion and reorganization are vital for cellular functions.
• Fluorescence cross-correlation spectroscopy (FCCS) is used to study diffusion and molecular interactions at low concentrations.

Purpose of the Study:

• To develop an economical method for simultaneously monitoring diffusion and complexation of multiple fluorophores.
• To enable four-color FCCS using a single detector and spectral deconvolution.

Main Methods:

• Utilized a super-continuum laser for customizable excitation wavelengths.
• Employed spectral fitting to analyze interactions of up to four overlapping fluorophores.
• Applied four-color FCCS to nanoparticles, lipid vesicles, and membrane-bound molecules.

Main Results:

• Demonstrated simultaneous monitoring of diffusion and interactions for up to four fluorophores.
• Successfully applied the method to polystyrene nanoparticles, lipid vesicles, and membrane-bound molecules.
• Observed induced aggregation of nanobeads and lipid vesicles with increasing buffer salinity.

Conclusions:

• The developed cost-effective four-color FCCS method allows simultaneous analysis of multiple fluorophores.
• This technique is adaptable for studying macromolecular complex formation in various systems.
• Offers wide applicability for research in model and living biological systems.