Search Thermo Fisher Scientific
Search Thermo Fisher Scientific
Qdot 800 probe is an excellent near-IR–fluorescent label with outstanding brightness and photostability for imaging and flow cytometry applications. With an emission maximum of ~800 nm, Qdot 800 probe can be excited using any laser line from 350 nm up to 633 nm or a standard Cy5.5 filter. Optimum imaging results with brighter signals are achieved with a Qdot 800 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.
Initial brightness | For best results use a Qdot-optimized filter and PBS or a mounting medium without antifade.
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Photostability in buffer |
633 | Cy5.5 | UV | 800 | ||
Laser line | Common filter set | Excitation max | Emission max |
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.
Histogram (gated) of human monocytes with CD38 Mouse Anti-Human mAb (clone HIT2) Qdot 800 Conjugate.
Histogram overlay plot of gated human monocytes, the black line represents cells labeled with CD38 Mouse Anti-Human mAb (clone HIT2) Qdot 800 Conjugate and the gray line represents unstained cells. Samples were acquired and analyzed using 405 nm excitation and a 780/60 band pass emission filter using the Attune Acoustic Cytometer Blue/Violet option.
We’ve developed functionalized versions of the Qdot 800 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 |
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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.