Qdot 655 probe

Qdot 655 probe is an excellent far red–fluorescent label with outstanding brightness and photostability for imaging and flow cytometry applications. With an emission maximum of ~655 nm, Qdot 655 probe can be excited using a 350, 488, 595, or 615 nm laser line or standard Cy5 filter. Optimum imaging results with brighter signals are achieved with a Qdot 655 filter or light cube.

Made from nanocrystals of semiconductor material, Qdot probes are broadly compatible with standard fluorescence techniques, but there are some novel aspects to their use that can be optimized to obtain the best possible results. In general they have an extremely broad excitation range and narrow emission with a large Stokes shift. Optimal brightness is generally achieved using a specific Qdot filter.

Organic fluorophores and Qdot probes can be readily combined in multiplexed flow cytometry or imaging studies. Longer-wavelength Qdot probes are also ideal for multiplexed western blots.

Qdot 655 probe dashboard

Initial brightness


For best results use a Qdot-optimized filter and PBS or a mounting medium without antifade.



Photostability in buffer


Qdot 655 products

The exceptional brightness and photostability of Qdot probes make it easier to detect low-abundance targets. With narrow and symmetric emission spectra, Qdot probes are also ideal for multiplexed fluorescence detection using a combination of Qdot probes and organic dyes.

BPAE cells were fixed and permeabilized using the Image-iT Fixation/Permeabilization Kit and incubated with Anti- ATP Synthase Subunit IF1 followed by GAM-QD655. Cells were labeled with ReadyProbes reagents NucBlue Live and ActinGreen 488, then mounted using ProLong Gold Antifade Reagent. Images were taken using the EVOS FL Auto Imaging System and a 40X CoverSlip corrected Objective.

Qdot 655 conjugation kits

We’ve developed functionalized versions of the Qdot 655 label for the preparation of custom conjugates of proteins and other biomolecules. The first—a carboxyl-derivatized form—can be coupled to amine groups of proteins and modified oligonucleotides. The second—an amine-derivatized PEG form—can be coupled to isothiocyanates and succinimidyl esters (or with native carboxylic acids using water-soluble carbodiimides).

Amine Aldehyde-, ketone, carboxylate or phosphate
Qdot probes and accessories

Qdot probes and accessories

Qdot Probes are made from nanocrystals of semiconductor material and are broadly compatible with standard fluorescence techniques, but there are some novel aspects to their use that can be optimized to obtain the best possible results. Learn more about Qdot Probes:


Molecular Probes Handbook

Cell stain tool

The significantly revised 11th Edition is the most complete fluorescence labeling and detection reference available. The Molecular Probes Handbook can help you achieve the best experimental results for your fluorescence labeling and detection experiments. View the handbook online or order your own copy.

Go to the Handbook online
Order your copy of the Handbook

Antifades and mounting media

Cell stain tool

High-performance antifade reagents like ProLong Antifade and SlowFade Antifade will inhibit the photobleaching of organic dyes but suppress the fluorescence of Qdot probes. A better solution for imaging Qdot probes is simply PBS or a clear, colorless toluene-based mounting medium formulated from acrylic resins without the addition of antifade components.

Order PBS, ph 7.4

Cell stain tool

Cell stain tool

Stain your own cell by using our simulation tool to develop reproducible results with many of our signature fluorescent dyes. Develop your multiplexing strategy for antibody probes, reactive dyes, and counterstains to create your perfectly labeled fluorescent cell.

Go to the cell stain tool

Fluorescence SpectraViewer


Plot and compare spectra and check the spectral compatibility for common fluorophores including all of the fluorescent probes from Thermo Fisher Scientific. The Fluorescence SpectraViewer tool is formatted for both microscope imaging and flow cytometry applications.

Go to the Fluorescence SpectraViewer

Not for resale. Super Bright Polymer Dyes are sold under license from Becton, Dickinson and Company.