Fluorescence and dye labeled peptides have been developed for in vivo biomedical imaging, protein binding and localization studies, etc. Fluorescence and dye can be attached to the peptide N-terminus directly (FITC always via be inserted an aminohexanoic acid (Ahx) or β-Ala linker between the fluorophore (fluoroscein) and the N-terminus of the peptide.), or to the Lys (or Cys) side chains in the peptide C-terminus or many other positions in the peptide.

ONTORES Peptides can provide many common used fluorescent and dyes peptides: such as FITC, FAM, TAMRA, NBD (7-nitrobenz-2-oxa-1, 3-diazole), Amc, Atto, Alexa Fluor, Bodipy, Cy3, Cy5......

Each fluorescence and dye labeled peptide delivered as a lyophilized powder in foil covered tube.

Fluorescein isothiocyanate (FITC) is an amine reactive derivative of fluorescein dye has been extensively used to label peptides and proteins.

Cy3 and Cy5 are dyes with extremely high extinction coefficients and fluorescence. Thus, they are especially suitable for very sensitive localisation assays of peptides in cells.Their disadvantage is the high instability of the molecules under peptide synthesis conditions.therefore the yields are comparatively low.