Shop All Cell Viability Kits

LIVE/DEAD™ Fixable Near-IR Dead Cell Stain Kit, for 633 or 635 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Near-IR Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a red laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability
• Robust—staining pattern is the same before and after fixation
• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Near-IR Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Near-IR Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable Near-IR stain was selected based on its fluorescent properties to provide a bright signal when excited with a red laser. The near-IR fluorescent reactive dye has an excitation maximum of ~633 nm making it ideal for use with the red or HeNe laser with an emission of ~750 nm. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, it is an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

LIVE/DEAD™ Fixable Far Red Dead Cell Stain Kit, for 633 or 635 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Far-Red Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a red laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability
• Robust—staining pattern is the same before and after fixation
• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Far-Red Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Far-Red Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable Far-Red Stain was selected based on its fluorescent properties to provide a bright signal when excited with a red laser. The far-red fluorescent reactive dye has an excitation maximum of ~633 nm making it ideal for use with the red or HeNe laser with an emission of ~655 nm. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, it is an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

LIVE/DEAD™ Fixable Green Dead Cell Stain Kit, for 488 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Green Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a blue laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability

• Robust—staining pattern is the same before and after fixation

• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Green Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Green Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable Green stain was selected based on its fluorescent properties to provide a bright signal when excited with a blue 488 nm laser. The green-fluorescent reactive dye has an excitation maximum of ~495 nm making it ideal for use with the blue laser and an emission of ~520 nm allowing collection in the FITC channel. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, it is an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

alamarBlue™ HS Cell Viability Reagent (Invitrogen™)

alamarBlue HS Cell Viability Reagent is a ready-to-use resazurin-based solution that functions as a cell health indicator by using the reducing power of living cells to quantitatively measure viability. Upon entering living cells, resazurin is reduced to resorufin, a compound that is red in color and highly fluorescent. High background fluorescence caused by various contaminants reduces the performance of resazurin-based reagents. To improve the performance, an innovative purification process was developed that removes these contaminants. This highly purified, non-toxic resazurin was used in the standard alamarBlue formulation, creating the multiple-component alamarBlue HS Cell Viability Reagent. Changes in viability can be easily detected using either an absorbance- or fluorescence-based plate reader. The alamarBlue HS Cell Viability Reagent has broad applicability and can be used with various human and animal cell lines, bacteria, plant, and fungi.

alamarBlue HS Cell Viability Reagent features include:
Removal of contaminants from resazurin—displays a >50% reduction in background fluorescence
Signal-to-background ratio increased by >100%—results in large assay signal window
Highly sensitive reagent with a linear response—detects as few as 20 cells per well
Convenient add-and-read format—no mixing, no washing, no cell lysis, and compatible with either fluorescence- or absorbance-based instrumentation
Measures viability from many diverse cell types—including mammalian cells, bacteria, plant, and fungi

Measuring changes in cell viability is a fundamental method for assessing cell health, determining genotoxicity, and evaluating anti-cancer drugs. Cell health can be monitored by detecting changes in several key indicators, including changes to plasma membrane integrity, DNA synthesis, DNA content, enzyme activity, presence of ATP, and cellular reducing environment.

Monitoring changes to the cellular reducing environment or metabolic activity by using resazurin-based reagents is a well-established and reliable indicator of cell viability or death. Upon entering living cells, the cellular reducing environment reduces resazurin to resorufin, a compound that is red in color and highly fluorescent. Viable cells continuously convert resazurin to resorufin, increasing the overall fluorescence of the medium surrounding the cells. Additionally, the conversion of resazurin to resorufin results in a pronounced color change, thus cell viability can also be detected using absorbance-based plate readers.

As a consequence of the synthesis and manufacturing processes, all resazurin-based reagents contain a detectable amount of resorufin contamination. The amount of contamination can vary greatly between sources of the material and manufacturing conditions, contributing to differences in detectable background fluorescence. More importantly, the contaminating resorufin reduces the signal to background ratio and dynamic range of the assay. An innovative process was developed that removes the contaminating resorufin, resulting in the highly pure resazurin used in alamarBlue HS Cell Viability Reagent.

alamarBlue HS Cell Viability Reagent is a complete add-and-read, non-toxic reagent that does not require cell lysis. The highly purified resazurin used for alamarBlue HS reagent results in a >50% decrease in background fluorescence and a >100% increase in the signal-to-background ratio. Since no lysis is required, the diluted alamarBlue HS solution can be removed and replaced with complete growth medium for further culturing of the cells. Similar to alamarBlue reagent, alamarBlue HS reagent displays an extended viability detection time window for a wide variety of organisms and thus can be used with various human and animal cell lines, bacteria, plant, and fungi, resulting in quantitative measurement of cell viability and proliferation.

LIVE/DEAD™ Cell Imaging Kit (488/570) (Invitrogen™)

The LIVE/DEAD® Cell Imaging Kit is a sensitive two-color fluorescence cell viability assay optimized for FITC and Texas Red® filters. Quick and easy to use, the kit allows discrimination between live and dead cells with two probes that measure recognized parameters of cytotoxicity and cell viability—intracellular esterase activity and plasma membrane integrity.

The LIVE/DEAD® Cell Imaging Kit *488/570* offers:

Fast, simple determination of live and dead cells

• Accuracy with convenience
• Sensitive probes ideal for FITC and Texas Red filters


Dual Probe-Based Assay for Imaging Platforms
Just like our popular LIVE/DEAD® Viability/Cytotoxicity assay, the new LIVE/DEAD® Cell Imaging Kit is based on a cell-permeable dye for staining of live cells and a cell-impermeable dye for staining of dead and dying cells, which are characterized by compromised cell membranes. To adapt this important assay for imaging platforms, the LIVE/DEAD® Cell Imaging Kit components were optimized for the common green and red imaging filters used with FITC and Texas Red. The live cell component produces an intense, uniform green fluorescence in live cells (ex/em 488 nm/515 nm). The dead cell component produces a predominantly nuclear red fluorescence (ex/em 570nm/602 nm) in cells with compromised cell membranes, a strong indicator of cell death and cytotoxicity (Fig 1).

Quick, Exact Determination of Viability and Cytotoxicity
The LIVE/DEAD® Cell Imaging kit provides very sensitive detection of key measures of cell health: viability, live/dead ratio, and cytotoxicity. The components of the LIVE/DEAD® Cell Imaging kit are configured for ease of use with minimal dilutions.

Assay Principle
With the LIVE/DEAD® Cell Imaging Kit, live cells are distinguished by the presence of ubiquitous intracellular esterase activity as determined by the enzymatic conversion of the virtually non-fluorescent cell-permeant calcein AM to the intensely fluorescent calcein, which is well-retained within live cells. The red component of the LIVE/DEAD® Cell Imaging Kit is cell-impermeant and therefore only enters cells with damaged membranes. In dying and dead cells a bright red fluorescence is generated upon binding to DNA. Background fluorescence levels are inherently low with this assay technique because the dyes are virtually non-fluorescent before interacting with cells. The fluorophores in the LIVE/DEAD® Cell Imaging Kit were selected for their brightness, spectral properties (FITC and Texas Red filters), and ease of use. Packaged for workflow convenience, they allow for effortless and quick determination of the fractions of live and dead cells in a population.

See other Molecular Probes imaging tools and reagents

LIVE/DEAD™ Fixable Dead Cell Stain Sampler Kit (Invitrogen™)

LIVE/DEAD™ Fixable dead cell stains are used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. The stains in the sampler kit have been optimized and validated for use in flow cytometry.

• Stable—dyes are freeze-dried in separate vials to maintain stability
• Robust—staining pattern is the same before and after fixation
• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable dead cell stains in this sampler kit have been conveniently packaged in eight 40-test vials to help ensure the stability and performance of the dye over time. Amine-reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to use the vial completely once rehydrated or aliquot the solution and store at -80°C, avoiding freeze thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with formaldehyde or ethanol-based fixatives required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable dead cell stains are amine-reactive dyes that bind covalently to intracellular and extracellular amines, allowing the staining pattern to be preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable dead cell stains were selected based on their fluorescent properties to provide a bright signal when excited with the optimal lasers. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, these dead cell stains are an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dead cell stain reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable dead cell stains are available in a wide variety of colors to meet your multi-color panel needs. The sampler kit provides one vial (40 assays) of each of the eight dead cell stains available.

Find the LIVE/DEAD™ Fixable Dead Cell Stain that fits your needs:

• For UV lasers: blue
• For violet lasers: aqua, violet, or yellow
• For blue lasers: green or red
• For red lasers: far-red or near-IR

LIVE/DEAD™ Viability/Cytotoxicity Kit, for mammalian cells (Invitrogen™)

The LIVE/DEAD® Viability/Cytotoxicity Kit is a quick and easy two-color assay to determine viability of cells in a population based on plasma membrane integrity and esterase activity. The kit can be used in flow cytometry, fluorescence microscopy, and with fluorescence microplate readers.

Advantages Over Alternative Methods Include:


•  Faster
•  Safer
•  More sensitive
•  Less expensive

Easily Use with a Wide Variety of Techniques and Cell Types
Ubiquitous intracellular esterase activity and an intact plasma membrane are distinguishing characteristics of live cells. The LIVE/DEAD® Viability/Cytotoxicity Kit quickly discriminates live from dead cells by simultaneously staining with green-fluorescent calcein-AM to indicate intracellular esterase activity and red-fluorescent ethidium homodimer-1 to indicate loss of plasma membrane integrity. It is adaptable to most eukaryotic cells where cytotoxic conditions produce these cellular effects. The assay is useful with a variety of fluorescence-detection methodologies.

Sensitive, Safe, and Efficient

The LIVE/DEAD® Viability/Cytotoxicity Kit is more sensitive than Trypan blue exclusion, a commonly used method for live/dead cell discrimination. The cost-effective LIVE/DEAD® Viability/Cytotoxicity Kit is highly sensitive due to the bright fluorescence of both dyes upon interacting with either live (for calcein-AM) or dead (for ethidium homodimer-1) cells. Background levels are low due to the fact that both dyes are virtually non-fluorescent prior to interacting with cells.

LIVE/DEAD® Assays Available for a Broad Range of Applications
A selection of Invitrogen LIVE/DEAD® Viability Assays is offered for mammalian cells, bacteria, yeast and fungi, as well as Fixable Dead Cell Stain Kits for use in intracellular staining for flow cytometry. All LIVE/DEAD® assays provide quick, positive discrimination between viable and non-viable cells.

Related Link
•  Learn More and See the Full Range of LIVE/DEAD® Assay Products.

CellEvent™ Senescence Green Detection Kit (Invitrogen™)

The CellEvent Senescence Green Detection Kit consists of a fluorescent probe and optimized buffer that enable the image-based detection of senescent cells. The fluorescein-based probe contains two galactoside moieties, making it a target for β-galactosidase. Activation of β-galactosidase is commonly used as a biomarker for senescent cells. This hydrolase enzyme resides in lysosomes and converts β-galactosides into monosaccharides under acidic pH conditions. The enzymatically cleaved product is retained within the cell due to covalent binding of intracellular proteins and emits a fluorogenic signal that has absorption/emission maxima of 490/514 nm.

CellEvent Senescence Green Detection Kit features include:
• Reliable and quick fluorescent detection of senescent cells
• Greater sensitivity than traditional colorimetric x-gal
• Fluorescent signal is well retained and detected using standard Alexa Fluor 488/FITC filter sets
• Multiplex-enabled—fluorescent senescence probe can be multiplexed

Due to a limited replicative lifespan, normal cells enter cell cycle arrest, also known as cellular senescence. While in this senescent phase the cells remain metabolically active without undergoing cell death or division. They adopt a specific phenotypic that includes the appearance of multiple nuclei, increased vacuolization, expression of pH-dependent β-galactosidase, and morphological enlargement and extension. Senescence, through a variety of mechanisms, may play a role in tumor suppression, tumor progression, aging, and tissue repair.

Activation of β-galactosidase is commonly used as a biomarker for senescent cells. This hydrolase enzyme resides in lysosomes and converts β-galactosides into monosaccharides under acidic pH conditions. The activity is optimal at lysosomal pH 4, but conventional assays measure at pH 6. It has been shown that normalized β-galactosidase activity is twice as high in senescent cells as in pre-senescent cells regardless of the pH value used for testing.

A colorimetric substrate for β-galactosidase, 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (x-gal), has long been used to detect metabolic activity in cells in vitro. However, its use is limited due to inconsistent signal, length of assay, and inability to multiplex.

Therefore, we have developed a sensitive, fluorescent substrate for β-galactosidase that can be used for the detection of senescent cells. The CellEvent Senescence Green probe is a fluorescein-based reagent that contains two galactoside moieties, making it a specific target of β-galactosidase. The enzyme- cleaved product is retained within the cell due to covalent binding of intracellular proteins and emits a fluorogenic signal that has absorption/emission maxima of 490/514 nm.

The CellEvent Senescent Green Kit provides CellEvent Senescent Green probe and an optimized buffer for the detection of senescent cells in fixed samples. This probe can be multiplexed with other fluorescent reagents compatible with paraformaldehyde fixation.

CellROX™ Orange Flow Cytometry Assay Kit (Invitrogen™)

The CellROX™ Orange Flow Cytometry Assay Kit enables the flow cytometric detection of reactive oxygen species (ROS) in live cells. The kit includes the novel, fluorogenic CellROX™ Orange Reagent, as well as SYTOX™ Red Dead Cell Stain, N-acetyl cysteine (an antioxidant, for negative control), and tert-butyl hydroperoxide solution (TBHP, an inducer of ROS).

View a selection guide for all CellROX® Reagents and Kits.

The CellROX™ Orange Flow Cytometry Assay Kit features:

• Fluorogenic probe formulated for flow cytometry that is oxidized in the presence of ROS
• Multicolor compatibility—minimal overlap with fluorophores excited by other laser lines, allowing easy multiplexing with other reagents
• Simple protocol—cells can be stained in complete media or other appropriate buffer, no need for serum free media

The CellROX™ Orange Detection Reagent is cell-permeable and non-fluorescent or very weakly fluorescent while in the reduced state. Upon oxidation, the reagent exhibits a strong fluorogenic signal that has absorption/emission maxima of 545/565 nm and remains localized in the cytoplasm. When used together with the included SYTOX™ Red Dead Cell Stain, oxidatively stressed and nonstressed cells are reliably distinguished from dead cells by flow cytometry.

XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) (Invitrogen™)

XTT is used to assess cell viability as a function of redox potential. Actively respiring cells convert the water-soluble XTT to a water-soluble, orange colored formazan product. Unlike MTT, XTT does not require solubilization prior to quantitation, thereby reducing the assay time in many viability assay protocols. Moreover, the sensitivity of the XTT reduction assay is reported to be similar to or better than that of the MTT reduction assay.

LIVE/DEAD™ Fixable Blue Dead Cell Stain Kit, for UV excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Blue Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a UV laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability

• Robust—staining pattern is the same before and after fixation

• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Blue Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Blue Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable Blue Stain was selected based on its fluorescent properties to provide a bright signal when excited with a UV laser. The blue-fluorescent reactive dye has an excitation maximum of ~350 nm, making it ideal for use with an UV laser, and an emission of ~450 nm. By switching viability staining from a channel off of the blue 488 nm laser to the UV laser, you will free up a channel on your flow cytometer for other reagents that are difficult to find in colors other than FITC or PE. By using the UV laser, there is no spectral overlap issues with other common dyes, thus eliminating the need to compensate the viability stains from other stains in your panel. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, it is an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

LIVE/DEAD™ Fixable Red Dead Cell Stain Kit, for 488 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Red Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a blue laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability

• Robust—staining pattern is the same before and after fixation

• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Red Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Red Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable Red stain was selected based on its fluorescent properties to provide a bright signal when excited with a yellow, green, or blue 488 nm laser. The red-fluorescent reactive dye has an excitation maximum of ~595 nm, making it ideal for use with the yellow laser, and an emission of ~615 nm, allowing collection in the 610 or 630 BP filter. LIVE/DEAD™ Fixable Red Dead Cell stain is also excited well with the blue 488 nm laser. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, it is an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

ReadyProbes™ Cell Viability Imaging Kit, Blue/Red (Invitrogen™)

ReadyProbes® Cell Viability Imaging Kit (Blue/Red) is a ready-to-use kit that can quickly and easily determine the viability of cells. Just add 2 drops each of room temperature, stable NucBlue® Live reagent (Hoechst 33342) and propidium iodide to 1 mL of cell growth media, then determine viability by counting total vs dead cells. NucBlue® Live reagent stains the nuclei of all the cells and can be detected using a standard DAPI filter. Propidium iodide stains only the nuclei of cells with compromised plasma membrane integrity and is detected with a standard TRITC/RFP (orange) filter set. This kit is appropriate for fluorescence microscopy, fluorescence micro plate readers, and flow cytometry.

NucBlue® Live reagent: stains the nuclei of all cells; detected with a standard DAPI filter (excitation/emission maxima: 360/460 nm)
Propidium iodide: stains the nuclei of dead cells with compromised plasma membrane; detected with standard TRITC/RFP (orange) filter set (excitation/emission maxima: 535/617 nm)
See other ReadyProbes® reagents for cell staining
Learn more about other assays for cell viability

Suggestions for use
• NucBlue® Live reagent and propidium iodide can be added directly to cells in full growth media or a compatible buffer solution.
• In most cases, 2 drops/mL and an incubation time of 5 to 30 minutes will give bright nuclear staining; however, optimization may be needed for some cell types, conditions, and applications. In such cases, simply add more or fewer drops until the optimal staining intensity is obtained.

BacLight™ Green Bacterial Stain (Invitrogen™)

The BacLight Green (Cat. no. B-35000) and BacLight Red (Cat. no. B-35001) bacterial stains are fluorescent labeling reagents for detecting and monitoring bacteria. These two dyes are not nucleic acid stains. Bacteria stained with the BacLight Green and BacLight Red bacterial stains exhibit bright green and red fluorescence (absorption/emission ~480/516 and ~581/644 nm, respectively), and can be resolved using the appropriate flow cytometric channels or fluorescence microscopy filters. The BacLight bacterial stains are compatible with formaldehyde or alcohol fixation methods.

View additional information about all microbiological analysis products.

LIVE/DEAD™ Fixable Yellow Dead Cell Stain Kit, for 405 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Yellow Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a violet laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability

• Robust—staining pattern is the same before and after fixation

• Low compensation—minimal spectral overlap between other fluorophores

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Yellow Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Yellow Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Low compensation
The LIVE/DEAD™ Fixable Yellow Stain was selected based on its fluorescent properties to minimize compensation between other violet dyes and dyes that excite off of the 488 nm blue laser. The yellow-fluorescent reactive dye has an excitation maximum of ~405 nm, but it is excited well with the 405 nm violet laser, and it has an emission maxima of ~570 nm, so it can be collected in the second or third channel on most violet laser flow cytometers.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.