The Thermo Scientific DRAQ5 Fluorescent Probe is a far-red DNA stain for live or fixed cells and easy multiplexing with other fluorophores, such as cells expressing green fluorescent protein (GFP) fusion proteins.

DRAQ5 Fluorescent Probe is a far-red DNA stain for fluorescent cellular imaging applications with live or fixed cells. Because of its far-red excitation and emission, the DRAQ5 Stain can be multiplexed with many other fluorophores. It is commonly chosen to counterstain nuclei and measure DNA content in cell proliferation studies involving cells expressing green fluorescent protein (GFP) fusion proteins. DRAQ5 Fluorescent Probe is compatible with many existing protocols across a wide range of instrumentation platforms.

Features of the DRAQ5 Fluorescent Probe:

• DRAQ5 dye—a red-to-infrared fluorescent stain specific for DNA (nuclei and DNA quantitation)
• Convenient—provided as easy-to-use DRAQ5 dye solutions (5 mM)
• Cellular imaging—lipophilic and membrane permeable dye is effective for live-cell and fixed-cell staining and quantitation of DNA content
• Counterstain—ideal for use alongside other fluorophore reporters for fluorescence microscopy or high-content screening (HCS)

Applications:
• Flow cytometry
• Flow and laser scanning cytometry
• Live cell imaging
• Cell based assays

Properties of DRAQ5 Fluorescent Dye
• Structure: Proprietary
• Alternative names: Anthraquinone compound
• Chemical name(s): 1,5-bis{[2-(di-methylamino) ethyl]amino}-4, 8-dihydroxyanthracene-9,10-dione
• Molecular formula: Not available
• Molecular weight: 412.54
• Excitation wavelength: 647 nm line optimal (Exλmax = 646 nm)
• Emission wavelength: > 665 nm to infra-red > 800 nm (Emλmax = 681 nm/697 nm intercalated with dsDNA)
• Extinction coefficient: Not available
• CAS #: Not available
• Purity: > 99%
• Solubility: Soluble at working concentrations in water and typical buffers
• Reactive groups: None; binds DNA A-T minor groove, mimicking histone 2b distribution, resulting in 16 nm red-shift

Fluorescence cell-based assays, such as flow cytometry, in-cell ELISA, fluorescence microscopy and high-content imaging require a fluorescent label to identify individual cells. When using multiple fluorescent probes to detect different cellular targets or activities, each probe must have a fluorescent spectrum different than the other probes. The blue-fluorescent DNA-binding probes, Hoechst and DAPI are frequently used; however, these probes cannot be used when UV illumination is unavailable or other blue-emitting fluorescent probes are used. Therefore, nuclear probes that emit in a color other than blue are useful for cell identification and counting, and for determining nuclear morphology and DNA content.

DRAQ5 Fluorescent Probe emits in the far-red region, is lipophilic and crosses cell and nuclear membranes in live and fixed cells and tissues for rapid DNA staining. This stain is water-soluble, supplied ready to use and does not require RNase, cell lysis, or a washing step, making it compatible with automation. Because DNA staining is stoichiometric, the DRAQ5 Fluorescent Probe can be used for DNA content analysis in cell proliferation studies. DRAQ5 Fluorescent Probe is usually added as the last stain in a labeling procedure because no washing is required. Alternatively, add this probe in assay medium for a live cell assay.

Visualize staining your cell without wasting your reagents, antibodies, or time with our new Stain-iT Cell Staining Simulator.