Reporter Fluorescent Molecules in Biological Systems: The Current Overview

Volume 1 • Issue 4 • 1000e111 Biochem Anal Biochem ISSN:2161-1009 Biochem, an open access journal Labeling molecules without losing its activity has a long track in science. The first labeling method for detection of the biomolecules was the use of radioisotope entities like 32P, which have been successfully employed to study protein–protein, protein–DNA, protein–RNA and protein–ligand interactions. In the past years however, radioisotope utilization as label has declined due to safety and health concerns [1]. Various kind of fluorophore moieties as suitable alternative has been developed and widely accepted. Dyes such as rhodamine, fluoroscein, phycobiliproteins, nitrobenzoxadiazole, acridines, BODIPY and cyanine compounds or their derivates are most commonly used as a reporter molecule. The choice of fluorophore molecule to be used for detection depends on the sample type, substrate, the number of analyzed molecules in the experiments and light emission spectra characteristics [2]. Cyanine dyes, Cy3 and Cy5, are among are a good example of dyes used due to their brightness and ability to easily label proteins with ε-amino group of lysine residues [3]. Detection using the fluorescence labeling can be performed in two ways: by direct labeling (one antibody assay) or indirect labeling [4]. In the direct labeling method, the selected protein is labeled directly with a fluorophore (Cy3 or Cy5), which interacts with, immobilized on the surface of the chip, antibodies. This method allows simultaneous incubation of a reference sample with tested sample, both having different dyes attached [5].