Cytosolic and Nuclear Staining

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Flow Cytometry



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Nuclear (DRAQ5 and DRAQ7), cytoplasmic (DRAQ9) and whole cell (CyTRAK Orange) dyes are now available to facilitate cell analysis in flow cytometry, fluorescence microscopy, and high content screening. These dyes offer the convenience of far-red fluorescence emission and are compatible with multiple fluorophores. Traditional dyes require a UV laser, which can induce DNA damage and cell death due to high-energy excitation. However, these far-red, photostable dyes have minimal photobleaching, are non-toxic in culture, and are ideal for long-term, live imaging studies with minimal spectral overlap with visible-range fluorophores.

DRAQ5 staining of nuclear dsDNA using fluorescence microscopy DRAQ7 viability staining by flow cytometry Cytoplasmic staining by DRAQ9 excludes nuclear structures CyTRAK Orange differential nuclear and cytoplasmic staining
  1. DRAQ5 [NBP2-81125] Stains dsDNA in the cell nuclei (blue) to visualize cell division by fluorescence microscopy.
  2. DRAQ7  [NBP2-81126] Far-red fluorescent dye labels the nucleus of U2OS cells alongside AlexaFluor 488 conjugated beta-tubulin (green).
  3. DRAQ9 [NBP2-81128] Labels membranous and vesicular structures in the cytoplasm (green) while excluding the nuclei. This dye is useful for long-term cell tracking and cell painting for high content phenotypic screening.
  4. CyTRAK Orange [NBP2-81127] Counterstaining of fixed U2OS cells, shows differential nuclear and cytoplasmic staining. This dye is useful in high content, image-based screens.


Key Benefits of DRAQ and CyTRAK Dyes


DRAQ5, a nuclear stain, can be used to identify the various phases of the cell cycle. This far-red, highly permeable dye is ideal for labeling dsDNA in live cells without the requirement for pretreatment with RNase. DRAQ5 serves as an alternative to Hoechst 33342 and DAPI for nuclear staining and can be used in combination with GFP, FITC and DyLight®488.


DRAQ7 represents a far-red, non-toxic alternative to Propidium Iodide (PI) and 7-AAD for evaluating cell viability over prolonged periods. DRAQ7 will not stain intact, live cells. By binding only to dsDNA in cells with compromised cell membranes or dead cells, this dye can be combined with live cell dyes and used in combination with GFP, FITC or PE.


DRAQ9 is a far-red, cell-permeant dye that stains the cytoplasmic membranous and vesicular structures but not the nucleus in live cells. This nontoxic cytoplasmic dye can be used in cell painting or live cell tracking for long-term, high-content phenotypic assays. DRAQ9 can be used in combination with GFP and UV-excited probes.

CyTRAK Orange

CyTRAK Orange, an orange fluorescent dye, demonstrates differential staining of nuclear and cytosolic compartments and is used to assess cell-to-cell differences in cell location, cell perimeter, cell shape, and cell spread parameters. In flow cytometry, CyTRAK Orange can be used to identify and target distinct populations such as arrested/senescent cells from healthy cells. In multicolor assays, CyTRAK Orange is compatible with GFP, FITC, or Alexa Fluor® 488 using the 488 nm (blue laser) for co-excitation, as well as with the red fluorochromes APC, PE-Cy7, or APC-Cy7.



Excitation/Emission Max (nm)



Cell Staining

DRAQ5 646/697
SpectraViewer emission and excitation profile for DRAQ5 fluorescent dye.
Nucleus Live and fixed cells or tissue
DRAQ7 646/697
SpectraViewer emission and excitation profile for DRAQ7 fluorescent dye.
Nucleus Fixed, membrane compromised and dead cells
DRAQ9 655/697
Absorbance and fluorescence emission of DRAQ9 dye.
  • Fluorescence Microscopy
  • Live Imaging Microscopy
  • ICC/IF
Live or fixed cells

CyTRAK Orange

SpectraViewer emission and excitation profile for DRAQ7 fluorescent dye.
Nucleus (stronger intensity), Cytoplasm (weaker intensity) Live or fixed cells


Tocris offers a new Fluorogenic Red fluorescent taxol derivative for direct imaging of the microtubule cytoskeleton.


View Our Flow Cytometry Handbook »      Learn More About ICC


DRAQ5, DRAQ7, DRAQ9 and CyTRAK Orange are registered trademarks of BioStatus Limited.

DyLight is a trademark of Thermo Fisher Scientific Inc. and its subsidiaries.

Alexa Fluor® is a registered trademark of Molecular Probes, Inc, a Thermo Fisher Scientific Company.