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Fixable Viability Stains for Flow Cytometry & Microscopy

Wide selection of dye colors designed for dead cell labeling in flow cytometry
Stable, fixable staining
Covalent labeling withstands fixation and permeabilization, with no loss of signal
Unique dyes designed to fill in gaps between common fluorophores
Dyes validated as dead cell stains in fluorescence microscopy
A DNA-binding, fixable dead cell stain for flow or microscopy
Several combination staining kits are available with all-yeast stains combined with Live-or-Dye™ dead cell stains


Fixable and stable labeling of dead cells for flow cytometry or microscopy

Live-or-Dye™ Fixable Viability Stains are cell membrane impermeant amine-reactive dyes. The dyes enter dead cells that have compromised membrane integrity and covalently label free amines on intracellular proteins. On live cells, the dyes react with surface proteins, but these are much less abundant than intracellular proteins, resulting in low staining levels compared to dead cells. Live-or-Dye™ labeling is extremely stable, allowing the cells to be fixed and permeabilized without loss of fluorescence or dye transfer between cells. Live-or-Dye™ stains are offered in a wide selection of 14 colors for easy panel design. This includes spectrally unique dyes designed for taking advantage of enhanced multiplexing by spectral flow cytometry.

Live-or-Dye fixable viability stains
Figure 1. Principle of Live-or-Dye discrimination of live and dead cells.

Live-or-Dye™ Advantages

Live-or-Dye™ staining is extremely stable and is compatible with intracellular staining protocols without interference with immunostaining.

  • Wide selection of 14 dye colors for easy panel design
  • Exceptionally bright dyes for excellent live/dead separation
  • Withstands fixation and permeabilization
  • No loss of brightness after fixation
  • For flow cytometry or fluorescence microscopy
  • Dyes designed to fit gaps in spectral flow panels
  • The most options for the 633 nm and 808 nm lasers
  • Trial sizes and sampler kits available

Withstands fixation and permeabilization

Figure 2. A mixture of live and dead Jurkat cells were stained with Live-or-Dye™ 405/452. One sample was left unfixed (lower, light cyan plot), and another sample was fixed in 2% formaldehyde and permeabilized with 0.1% Triton® X-100 (upper, dark cyan plot). No loss of signal is seen in the dead cells. No transfer of dye to live cells is seen.

Live-or-Dye™ Fixable Viability Staining Kits

Cat. No.

Viability Dye

Compatible lasers (nm)

Optimal detection channels


32018, 32018-TLive-or-Dye™ 330/410355, 375BUV395
32002, 32002-TLive-or-Dye™ 350/448355, 375DAPI
32014,32014-TLive-or-Dye™ 375/600355, 375, 405Spectral scan, BUV615, BV605Developed for spectral cytometry
32003, 32003-TLive-or-Dye™ 405/452405Pacific Blue®, BV421, BV450
32009, 32009-TLive-or-Dye™ 405/545405AmCyan, BV510
32004, 32004-TLive-or-Dye™ 488/515488FITCValidated for microscopy
32012, 32012-TLive-or-Dye™ 510/550488, 532Spectral scanDeveloped for spectral cytometry
32005, 32005-TLive-or-Dye™ 568/583488, 532, 561PE, PIValidated for microscopy
32006, 32006-TLive-or-Dye™ 594/614488, 532, 561PI, PE-CF®594, PE-Texas Red®Validated for microscopy
32015, 32015-TLive-or-Dye™ 615/740633-640Spectral scan, APC-Cy®7Developed for spectral cytometry
32007, 32007-TLive-or-Dye™ 640/662633-640APCValidated for microscopy
32013, 32013-TLive-or-Dye™ 665/685633-640Spectral scan, AF700Developed for spectral cytometry
32008, 32008-TLive-or-Dye™ 750/777633-640, 785APC-Cy®7The brightest dye for the APC-Cy®7 channel
32011, 32011-TLive-or-Dye™ 787/808785, 808APC-Cy®7, IR800

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Widest range of colors for easy panel design

Live/dead stains are useful probes to include in flow cytometry panels because they allow intracellular fluorescence signal from dead cells with permeable plasma membranes to be excluded from analysis. However, the limited number of dye colors from other commercially available live/dead stains can make choosing the right fluorophores difficult when designing highly complex panels. Live-or-Dye™ Fixable Viability Staining Kits are offered in a wide selection of live/dead dye colors, allowing maximal flexibility when designing multi-color flow panels (Fig. 3)

Figure 3. Live-or-Dye™ kits are available with 14 bright and stable dye colors for multichannel flow cytometry.

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Spectrally Unique Dyes Designed for Spectral Flow Cytometry

Spectral flow cytometry is a rapidly growing technology with significantly enhanced multiplexing capabilities over conventional flow cytometry. Where conventional flow cytometer instruments can detect panels with more than a dozen fluorophores, spectral flow cytometers can accommodate panels with upwards of 40 dyes. Biotium offers spectrally unique Live-or-Dye™ stains designed specifically to take advantage of enhanced multiplexing by spectral flow ctyometry.

Live-or-Dye™ Stains for Spectral Flow

Learn more about spectral flow cytometry and our high-performance CF® dyes developed to fill emission gaps between available fluorophores.

Figure 4. Excitation and emission spectra of Live-or-Dye™ stains designed specifically for spectral flow cytometry. Dotted lines represent excitation spectra, while shaded areas represent emission spectra.

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New: Live-or-Dye™ Sampler Kits for Flow Cytometry

Live-or-Dye™ stains are available in two sampler kits, each containing five different dye colors, for excitation from all of the popular flow cytometry laser lines (see Live-or-Dye™ Sampler Kits table below). The Live-or-Dye™ Sampler Kit, Standard (32016) was designed for use on the most common flow cytometer laser and filter configurations, with dyes excitable by UV, Violet, Blue, Yellow-Green, and Red lasers. The Live-or-Dye™ Sampler Kit, Spectral (32017) was designed for use in spectral scanning flow cytometry. It contains dyes excitable by UV, Violet, Blue, and Red lasers, all of which have been validated on the Cytek® Aurora spectral cytometer, and chosen for their ability to fill the gaps in many spectral flow panels.

Live-or-Dye™ Fixable Viability Staining Kits – 250 assays, Live-or-Dye™ Sampler Kit, Standard
Live-or-Dye™ Fixable Viability Staining Kits – 250 assays, Live-or-Dye™ Sampler Kit, Spectral

Live-or-Dye™ Sampler Kits

Kit Name

Catalog No.

Included dyes: Ex/Em (Cat No.)


Live-or-Dye™ Fixable Viability Sampler Kit, Standard32016• 350/448 (32002A)
• 405/545 (32009A)
• 488/515 (32004A)
• 568/583 (32005A)
• 640/662 (32007A)
Designed for use on most standard flow cytometry laser and filter configurations
Live-or-Dye™ Fixable Viability Sampler Kit, Spectral32017• 350/448 (32002A)
• 375/600 (32014A)
• 510/550 (32012A)
• 615/740 (32015A)
• 665/685 (32013A)
Designed for use in spectral flow cytometry, to fill in gaps between common fluorophores

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Bright and photostable dyes for microscopy

It is often very useful to identify dead cells for microscopic analysis as well, particularly when performing live-cell imaging experiments. In microscopy, live/dead stains allow unambiguous visual discrimination of dead cells. Live-or-Dye™ Fixable Viability Staining Kits are bright and photostable dyes that work just as well for microscopy as they do for flow cytometry, with negligible signal in live cells and strong signal in dead cells (Fig. 5).

Four stains have been validated for fluorescence microscopy. The other  dyes are expected to work as well, as long as the microscope has the appropriate excitation and emission settings.

Live-or-Dye™ Stains validated for fluorescence microscopy

Figure 5. Ethanol-treated HeLa cells stained with Live-or-Dye™ Fixable Dead Cell Stains. Dead cells stain brightly with Live-or-Dye™, while live cells show minimal staining. Nuclei are stained with Hoechst (blue).

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Live-or-Dye NucFix™ Red is a unique, cell membrane impermeable dye that specifically stains the nuclei of dead cells.

Unlike other commonly used nuclear stains such as propidium iodide (PI) or DRAQ7™, Live-or-Dye NucFix™ labeling is covalent, so the dye doesn’t transfer between cells after fixation. Live-or-Dye NucFix™ Red can be used for flow cytometry or fluorescence microscopy (Fig. 6).

Live-or-Dye NucFix™ Red Staining Kit – 50 assays
Live-or-Dye NucFix™ Red Staining Kit – 200 assays
live or dye nucfix red
Figure 6. Discrimination of live and dead cells using Live-or-Dye NucFix™ Red Fixable Viability Stain. A. Flow cytometry of live (open peak) or heat-killed (solid peak) Jurkat cells stained with Live-or-Dye NucFix™ Red. B. Ethanol-treated HeLa cells stained with NucFix™ Red. Killed cells show bright red nuclear staining, compared to no staining seen in live cells. Nuclei are stained with Hoechst (blue).

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Yeast specific kits include a Live-or-Dye™  stain with a yeast or fungal all-cell stain.

The Yeast Live-or-Dye™ Live/Dead Staining Kit combines a cell-permeant green dye, Thiazole Orange, which concentrates in the nucleus of live cells, with Live-or-Dye™ 568/583 (Fig. 7). Co-staining with the two dyes allows live/dead discrimination of yeast by fluorescence microscopy or flow cytometry.

Yeast Live-or-Dye Fixable Live/Dead Staining Kit
Figure 7. In the Yeast Live-or-Dye™ Fixable Live/Dead Staining Kit, Thiazole Orange gives nuclear-concentrated staining in all cells (green), while Live-or-Dye™ 568/583 specifically stains dead cells red (yellow in the merge).

The Yeast Viability Staining Kits take advantage of the unique fungal cell wall, by combining a Live-or-Dye™ dead cell stain with a fluorescent conjugate of the cell wall probe Concanavalin A (Con A) (Fig. 8). These kits are available in 3 color combinations for maximum experimental flexibility.

Yeast Viability Staining Kit
Figure 8. The Yeast Viability Staining Kit (Red/Far-Red) contains CF®640R Con A, which binds to the cell wall of all yeast (blue), with Live-or-Dye™ 568/583, which stains dead cells red.

Catalog No.Kit NameLive-or-Dye™ ColorOther Dye
31064 Yeast Live-or-Dye™ Fixable Live/Dead Staining KitLive-or-Dye™ 568/583 (stains dead cells red)Thiazole Orange (stains all cells green)
31063-1 Yeast Viability Staining Kit (Green/Red)Live-or-Dye™ 594/614 (stains dead cells red)CF®488A ConA (stains all cell walls green)
31063-2Yeast Viability Staining Kit (Red/Blue)Live-or-Dye™ 405/452 (stains dead cells blue)CF®594 ConA (stains all cell walls red)
31063-3Yeast Viability Staining Kit (Red/Far-Red)Live-or-Dye™ 568/583 (stains dead cells red)CF®640R ConA (stains all cell walls far-red)

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Draq7 is a trademark of Biostatus, Ltd. Texas Red and Pacific Blue are registered trademarks of Thermo Fisher Scientific. Cy Dye is a registered trademark of Cytiva.

Live-or-Dye™ Fixable Viability Staining Kits

From: $74 Sizes: 50 assays, 200 assays, 250 assaysCatalog #:
, 32017, 32018-T, 32002-T, 32014-T, 32003-T, 32009-T, 32004-T, 32012-T, 32015-T, 32005-T, 32007-T, 32006-T, 32013-T, 32008-T, 32011-T, 32018, 32002, 32014, 32003, 32009, 32004, 32012, 32005, 32006, 32015, 32007, 32013, 32008, - 32011View allHide

Live-or-Dye NucFix™ Red Staining Kit

From: $75 Sizes: 50 assays, 200 assaysCatalog #:
, - 32010-TView allHide

Yeast Live-or-Dye™ Fixable Live/Dead Staining Kit

From: $439 Sizes: 1,000 assaysCatalog #: 31064

Yeast Viability Staining Kit

From: $475 Sizes: 1,000 assaysCatalog #:
, 31063-2, - 31063-3View allHide