Labeling of proteins with fluorescent probes: Photophysical characterization of dansylated bovine serum albumin

Abstract

Fluorescence spectroscopy is a widely used technique in biophysical studies. One of the strategies frequently used consists of labeling biomolecules with fluorescent probes, which have distinctive photophysical properties. This methodology allows the study of a wide variety of structural features of the biomolecule. We describe a simple laboratory activity for undergraduate Biophysical Chemistry courses. The experimental work includes two activities: labeling BSA with dansyl chloride and analyzing the resulting absorption and fluorescence spectra. The discussion of these activities helps students to understand the basis of fluorescence spectroscopy with emphasis in the application to biological systems. © 2003 by The International Union of Biochemistry and Molecular Biology.