A comparative study of LED-induced fluorescence and laser-induced fluorescence in SDS-CGE: application to the analysis of antibodies.

LEDs present an alternative to lasers in LIF detection with CE, resulting in LED-induced fluorescence (LEDIF). LEDs are much less expensive, consume less energy and are more stable. In addition, LED light sources allow a greater range of wavelengths to better match the maximum wavelength for the fluorescence of the dye. Antibodies were largely studied in SDS capillary gel electrophoresis (SDS-CGE) and LIF detection with different dyes to label the proteins. In this work, our goal is to show that LEDs can advantageously replace lasers. We used 5-carboxytetramethylrhodamine succinimidyl ester (5-TAMRA.SE), 3-(2-furoyl)-quinoline-2 carboxaldehyde (FQ), and naphthalene-2,3-dialdehyde (NDA) to label IgG and we compared the LIF sensitivity with that obtained from LEDIF. We measured that the LOD values of LEDIF are identical to that obtained with the wavelength equivalent laser, and for 5-TAMRA.SE analysis, LOD values are about six times better than when the classical 488 nm laser was used.