Noncovalent Labeling of Biomolecules with Red and Near- Infrared Dyes

Abstract

Biopolymers such as proteins and nucleic acids can be labeled with a fluorescent marker to allow for their detection. Covalent labeling is achieved by the reaction of an appropriately functionalized dye marker with a reactive group on a biomolecule. The recent trend, however, is the use of noncovalent labeling that results from strong hydrophobic and/or ionic interactions between the marker and biomolecule of interest. The main advantage of noncovalent labeling is that it affects the functional activity of the biomolecule to a lesser extent. The applications of luminescent cyanine and squarylium dyes are reviewed.

Keywords

• Cyanine dyes
• squarylium dyes
• protein
• DNA
• capillary electrophoresis
• fluorescence.