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Do you offer Cy3B Labeled Oligos?

Yes, we do offer Cy3B oligo labeling services.This modification must be attached to the oligo after synthesis using NHS Ester chemistry. NHS Esters react with free primary amines and result in stable, covalent attachment. A primary amine is therefore added to the oligo during synthesis to permit reaction with the desired NHS Ester. 

Minimum synthesis scale: 250nmol, dual HPLC purification is required.

Cy3B in FP & FRET assays

Fluorescence polarization (FP) assays take advantage of the natural molecular rotation of species in an aqueous environment and this format is particularly suitable for assays that measure the binding of small or mid-size ligands to larger biomolecules.

Cy3B is a bright version of the standard Cy3 dye, and is ideally suited to fluorescence polarization (FP) applications, owing to its fluorescence lifetime of 2.8 ns and its high fluorescence intensity.

It demonstrates a larger polarization range than conventional fluors such as fluorescein. Its brightness also makes it useful in fluorescence resonance energy transfer (FRET) applications. It has a stable signal in a variety of aqueous solvents and low non-specific binding, which is particularly important in assays with small signal windows.

CyDye Molecular weight Abs. max (nm) Em. max (ns) Lifetime (ns) Quantum yield Molar extinction coefficient (M-1cm-1)
Cy3B 658 558 572 2.8 0.7 130,000
Cy5 791.9 646 664 1.0 0.27 250,000