LIVE/DEAD Cell Viability Assays

On this page:

• Selection guide of LIVE/DEAD cell viability assays
• LIVE/DEAD cell viability assays
• LIVE/DEAD bacterial viability assays
• LIVE/DEAD fungi and yeast viability assays
• LIVE/DEAD fixable viability dyes for flow cytometry

LIVE/DEAD cell viability kits offer two- or three-color discrimination of live from dead populations based on membrane integrity, esterase activity, metabolic activity, or structural segmentation. These viability kits been have optimized for use on fluorescence microscopy, flow cytometry, and microplate readers.

LIVE/DEAD Viability/Cytotoxicity Kit is a quick and easy two-color viability assay based on membrane integrity and esterase activity (Figure 1). Plasma membrane integrity is determined by ethidium homodimer-1 which enters cells with a compromised plasma membranes to bind DNA and emit a red fluorescence; live cells are identified by Calcein AM, a fluorogenic cell-permeant dye that is converted to a green fluorescence after interaction with intracellular esterase’s.

LIVE/DEAD Cell Viability Assay Kit, C₁₂ Resazurin/SYTOX Green is a simple, two-color viability assay to identify metabolically active cells from dead and damaged cells (Figure 2). In metabolically active cells, C₁₂-resazurin is reduced to C₁₂-resorufin to emit a red fluorescence. C₁₂-resazurin is the lipophilic version of resazurin that is more permeable to live cells and the C₁₂-resorufin product is better retained in cells. The SYTOX Green dye enters the compromised plasma membrane of dead and dying cells, and binds DNA resulting in a green fluorescence. Cells that have undergone damage, will display a reduced red and green fluorescence.

LIVE/DEAD kits for bacterial viability are convenient and easy-to-use two-color fluorescent assays to discriminate between live and dead bacterial populations based on membrane integrity. These kits contain SYTO 9 green-fluorescent stain and PI red-fluorescent stain that differ in their ability to enter bacteria. When used alone, SYTO 9 will stain all bacteria in a population regardless of membrane integrity; however, PI will only enter bacteria with a compromised membrane causing reduced SYTO 9 fluorescence. With an optimized mixture, dead bacteria will fluoresce red, while live bacteria will fluoresce green. These assays have been optimized for use on fluorescence microscopy (Figure 3), flow cytometry (Figure 4), and microplate readers.

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LIVE/DEAD Yeast Viability Kits provide easy, reliable, and quantitative discrimination in pure or mixed cultures. Each kit offers two-color discrimination based on membrane integrity or metabolic activity and fungal cell wall labeling.

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The Yeast Viability Kit (Figure 5) contains FUN 1 dye, that uses the plasma membrane integrity and metabolic activity of live populations to convert the yellow-green-fluorescent intracellular staining to red-orange intravacuolar structures, and Calcofluor White M2R which labels cell-wall chitin with a blue-fluorescence.

The LIVE/DEAD FungaLight Yeast Viability Kit uses 2 nucleic acids stains - SYTO9 green-fluorescent stain and PI red-fluorescent stain (Figure 6). When used alone, SYTO 9 will stain all yeast in the population; while PI only enters yeast with a damaged membrane resulting in reduced SYTO 9 fluorescence. As a result, live yeast with uncompromised membrane will fluoresce green whereas dead yeast with compromised membrane will fluoresce red.

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LIVE/DEAD Fixable Dead Cell Stain Kits allow you to accurately distinguish live and dead cells when performing intracellular staining in flow cytometry (Figure 7). Additionally, the dyes in the kits react covalently with protein so that the discrimination is completely preserved following fixation of the sample by formaldehyde, a treatment that inactivates pathogens.

Learn more about LIVE/DEAD Fixable Dead Cell Stain Kits

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