Whole-column fluorescence-imaged capillary electrophoresis.

Area of Science:

• Analytical Chemistry
• Biophysical Chemistry
• Separation Science

Background:

• Capillary electrophoresis (CE) is a powerful separation technique.
• Whole-column imaging offers potential for enhanced detection.
• Developing sensitive and efficient imaging CE methods is crucial for analyzing fluorescent analytes.

Purpose of the Study:

• To develop and validate an axially illuminating whole-column fluorescence imaging capillary electrophoresis (CE) system.
• To assess the system's performance for separating and analyzing fluorescent compounds and labeled proteins.
• To evaluate the system's utility for comparing the photodegradation resistance of fluorescent molecules.

Main Methods:

• An experimental setup using a 6 cm Teflon capillary (42 µm ID) as the separation column.
• Axial illumination with 488 nm Ar+ laser light coupled via optical fiber.
• Total internal reflection of excitation light within the capillary.
• Whole-column fluorescence imaging using a charge-coupled device (CCD) camera.
• Testing with fluorescein isothiocyanate (FITC), 5-carboxyfluorescein, and FITC-labeled proteins.

Main Results:

• Demonstrated successful whole-column fluorescence imaging CE.
• Achieved fast and sensitive separation of fluorescent compounds and FITC-labeled proteins.
• Validated the system for rapid assessment of photodegradation resistance in fluorescent compounds.

Conclusions:

• The developed axially illuminating whole-column fluorescence imaging CE is a rapid and sensitive analytical tool.
• The system provides a simple and efficient method for comparing photodegradation of fluorescent compounds.
• This technique holds promise for the analysis of fluorescent analytes and material stability studies.