Shop All Cell Viability Kits

BacLight™ Red 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.

PrestoBlue™ Cell Viability Reagent (Invitrogen™)

Get high quality cell viability results and instant time savings with PrestoBlue® Cell Viability Reagent. PrestoBlue® is a ready to use cell permeable resazurin-based solution that functions as a cell viability indicator by using the reducing power of living cells to quantitatively measure the proliferation of cells. When added to cells, the PrestoBlue® reagent is modified by the reducing environment of the viable cell and turns red in color, becoming highly fluorescent. This color change can be detected using fluorescence or absorbance measurements.

The PrestoBlue® Cell Viability Reagent allows you to:

• Save time with an incubation step as short as 10 minutes.
• Obtain high quality results with a large dynamic range
• Experience convenience with the add and read homogenous format
• Monitor living cells and perform downstream functional assays


10 Minute Incubation
The PrestoBlue® Cell Viability Reagent is the only live-cell viability reagent on the market able to provide robust data typically in as little as 10 minutes following reagent addition. All other resazurin-based cell viability reagents on the market require a one to four hour incubation with the reagent prior to obtaining data.

High Quality Results
Based on the cell type and incubation time, PrestoBlue® Cell Viability Reagent can detect as few as 12 cells per well in a 384 well plate. After ten minutes of incubation the PrestoBlue® Reagent can linearly detect cells down to 98 cells⁄well with a Z’ value of greater than 0.5.

Homogenous Assay Format
The PrestoBlue® Cell Viability Reagent is an addition-only reagent. Without the cell lysis or solubilization steps required by other assays on the market, hands-on time is minimized.

Live Cell Assay
The PrestoBlue® Cell Viability Reagent does not require cell lysis. Cells may be incubated for up to 24 hours in the presence of PrestoBlue® Cell Viability Product. Simply remove the reagent from the cells and replace it with growth medium for further proliferation.

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

The LIVE/DEAD™ Fixable Aqua 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 Aqua 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 Aqua 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 Aqua 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 aqua-fluorescent reactive dye has an excitation maximum of ~375 nm, but it is excited well with the 405 nm violet laser, and it has an emission maxima of ~512 nm, so it can be collected in the second 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.

CyQUANT™ XTT Cell Viability Assay (Invitrogen™)

The CyQUANT XTT Cell Viability Assay is a complete, optimized assay that generates a consistent colorimetric detection of viable mammalian cells. The assay kit consists of two reagents, XTT Reagent and Electron Coupling Reagent. XTT Reagent is used to assess cell viability as a function of cellular redox potential, and the electron coupling reagent improves the dynamic range of the assay.

The assay is sufficient for ten 96-well plates and consists of 10 bottles of XTT Reagent and 10 tubes of Electron Coupling Reagent. One bottle of each (sufficient for one 96 well plate) are thawed, mixed together, added to cells, and incubated. The viability signal is detected using an absorbance-based microplate reader. In actively respiring viable mammalian cells, the water-soluble XTT reagent is reduced and converted to an orange-colored formazan product.

More tools for microplate-based detection of viability ›

Features of the CyQUANT XTT Cell Viability Assay include:
• Highly reproducible, absorbance-based viability assay
• Improved dynamic range and sensitivity compared to other colorimetric viability assays
• Simple mix-and-read format, configured for one 96-well plate at a time
• Non-toxic, continuous assay—multiple time points can be collected, no cell lysis

Measuring changes in cell viability is a fundamental method for assessing cell health, determining genotoxicity, and evaluating anti-cancer drugs. In addition to being cost effective, colorimetric viability assays generate consistent results with low well-to-well variability. Unlike other commercially available colorimetric mammalian cell viability assays, XTT-based assays display a high dynamic range and low variability. In addition to improved performance, the assay is a continuous assay and requires no cell lysis or solubilization.

The CyQUANT XTT Cell Viability Assay is a complete and optimized kit for the detection of mammalian cell viability. The assay kit includes XTT Reagent (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) and Electron Coupling Reagent. The XTT reagent, which is a tetrazolium-based compound, is sensitive to cellular redox potential and in the presence of actively respiring cells converts from a water-soluble compound to an orange-colored formazan product. The sensitivity and consistency of the assay is significantly increased when used with the electron coupling reagent.

Since no cell lysis or solubilization are required for detection, the XTT assay can be employed as a continuous assay and several time points can be analyzed. Additionally, the CyQUANT XTT assay generates viability results from various types of cell lines, including primary and suspension cells.

For each 96-well plate, one bottle of XTT Reagent and one tube of Electron Coupling Reagent are thawed, mixed to create a stock solution, and added to cells, with cell viability detected after a 2–4 hour incubation. The assay kit supplies all the materials needed for ten 96-well plates.

It is recommended that the XTT/Electron Coupling reagent stock solution be used soon after mixing. Assay performance is compromised and sensitivity is reduced if the stock solution is kept at room temperature for extended periods of time or subject to cycles of freeze/thaw. To ensure assay performance and reproducibility, the CyQUANT XTT Cell Viability Assay consists of separate XTT and Electron Coupling reagents that are mixed.

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.

Tali™ Viability Kit - Dead Cell Red (Invitrogen™)

The Tali® Viability Kit - Dead Cell Red is a ready-to-use solution of propidium iodide (PI) that has been validated for use with the Tali® Image-Based Cytometer. PI is a live cell-impermeant fluorogenic DNA-binding dye that has been extensively used to identify necrotic cells.

Key Features of Tali® Viability Kit - Dead Cell Red:

• Impermeant to live cells
• Easily enters and binds to nucleic acids in necrotic cells

After staining a cell population using Dead Cell Red™, dead cells display red fluorescence upon excitation. Tali® Viability Kit - Dead Cell Red can be used to identify dead cells in a population of unstained cells, or in a population of GFP-expressing cells.

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.

CellROX™ Deep Red Flow Cytometry Assay Kit (Invitrogen™)

The CellROX™ Deep Red Flow Cytometry Assay Kit enables the flow cytometric detection of reactive oxygen species (ROS) in live cells. The kit includes the novel, fluorogenic CellROX™ Deep Red Reagent, as well as SYTOX™ Blue 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™ Deep Red 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™ Deep Red 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 644/665 nm and remains localized in the cytoplasm. When used together with the included SYTOX™ Blue Dead Cell Stain, oxidatively stressed and non-stressed cells are reliably distinguished from dead cells by flow cytometry.

Tali™ Cell Cycle Kit (Invitrogen™)

The Tali® Cell Cycle Kit includes a ready-to-use reagent that, when used with the Tali® Image-Based Cytometer, provides a convenient and accurate determination of the percentage of cells in each phase of the cell cycle. This single-addition reagent is composed of propidium iodide (PI), RNase A, and Triton X-100.

The Tali® Cell Cycle Kit offers a simple workflow:

• The pre-mixed reagent can be stored at room temperature and used when your cells are ready
• Simply fix your cells, add the reagent, incubate, and visualize
• Cell cycle data can be analyzed on the Tali® instrument or exported as a .csv or .fcs file for analysis with various modeling software

Fluorescent detection of cellular DNA as a cell-cycle phase indicator
PI, a red fluorescent dye, binds to DNA by intercalating between the bases with the little or no sequence preference. Consequently, the degree of fluorescence is proportional to the amount of cellular DNA, which itself is indicative of cell cycle phase (as cells progress through the cell cycle, the amount of DNA ultimately doubles). PI will also label RNA, so the addition of RNase A is necessary for accurate determination of the percentage of cells in each phase of the cell cycle.

After fixing your cells, simply add the optimized Tali® Cell Cycle reagent, incubate for 30 minutes in the dark, and then analyze on the Tali® Image-Based Cytometer. The cell cycle data from the Tali® Image-Based Cytometer can be analyzed on the instrument or exported in either .csv or .fcs format, and analyzed using cell cycle modeling software (such as ModFit or MultiCycle).

LIVE/DEAD™ BacLight™ Bacterial Viability and Counting Kit, for flow cytometry (Invitrogen™)

The LIVE/DEAD™ BacLight™ Bacterial Viability and Counting Kit allows researchers to reliably distinguish and quantitate live and dead bacteria with the aid of a flow cytometer, even in a mixed population containing a range of bacterial types. This kit uses a mixture of two nucleic acid stains - green-fluorescent SYTO™ 9 dye and red-fluorescent propidium iodide - for viability determinations, and a calibrated suspension of microspheres for accurate sample volume measurements.

View additional information about all microbiology assays for flow cytometry.

LIVE/DEAD™ Sperm Viability Kit (Invitrogen™)

The LIVE/DEAD Sperm Viability Kit provides a novel fluorescence-based assay for analyzing the viability and fertilizing potential of sperm by fluorescence microscopy or flow cytometry. Membrane-permeant SYBR® 14 nucleic acid stain labels live sperm with green fluorescence, and membrane-impermeant propidium iodide labels the nucleic acids of membrane-compromised sperm with red fluorescence.

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

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.

PrestoBlue™ HS Cell Viability Reagent (Invitrogen™)

PrestoBlue 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 PrestoBlue formulation, creating the PrestoBlue HS Cell Viability Reagent. Changes in viability can be easily detected using either an absorbance- or fluorescence-based plate reader. The PrestoBlue HS Cell Viability Reagent has been optimized for the fast and reliable detection of mammalian cell viability.

PrestoBlue 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 10 cells per well
• Convenient add-and-read format—no mixing, no washing, no cell lysis, and compatible with either fluorescence- or absorbance-based instrumentation
• Optimized for reliable detection of mammalian cell viability in only 10 minutes

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. An innovative process was developed that removes the contaminating resorufin, resulting in the highly pure resazurin used in PrestoBlue HS Cell Viability Reagent. This highly pure resazurin produces a >50% decrease in background fluorescence and a >100% increase in the signal-to-background ratio. Mammalian cell viability can be detected after a 10-minute incubation with PrestoBlue HS Cell Viability Reagent. Since no lysis is required, the diluted PrestoBlue HS solution can be removed and replaced with complete growth medium, for further culturing of the cells.

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

ReadyProbes® Cell Viability Imaging Kit (Blue/Green) is a ready-to-use assay 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 NucGreen® Dead reagent 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 with a standard DAPI filter. NucGreen® Dead reagent stains only the nuclei of cells with compromised plasma membrane integrity and is detected using a standard FITC/GFP (green) filter set. This kit is appropriate for fluorescence microscopy, fluorescence microplate 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)
NucGreen® Dead reagent: stains only the nuclei of dead cells with compromised plasma membranes; detected with standard FITC/GFP (green) filter set (excitation/emission maxima: 504/523 nm)
See other ReadyProbes® reagents for cell staining
Learn more about other assays for cell viability

Suggestions for use
• NucBlue® Live and NucGreen® Dead reagents may 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.