Sample preparation and laser-induced fluorescence detection are two key steps of the analytical methodology to determine by capillary electrophoresis low concentrations of proteins in complex sample matrices. In this chapter the options of performing both steps in different ways are shown by detailing the analysis of the allergen β-lactoglobulin in food products for infants and the analysis of the isoforms of alpha 1-acid glycoprotein, a potential biomarker, in serum and secretome.
