All tags Functional Assay Kits A guide to cell viability, proliferation and apoptosis assays

A guide to cell viability, proliferation and apoptosis assays

Cell viability, proliferation and apoptosis: a comparison

​Determining the viability of cultured cells in an essential process prior to to any cell-based study: only a healthy culture will show reliable and reproducible results. Quantification of cellular proliferation can also help to determine optimal culture conditions as well as the cytotoxic effect that some treatments have on the overall cell population.

Cell viability, proliferation and apoptosis are generally grouped together despite the fact that they measure different parameters. It is important to understand what cellular event you are trying to detect or measure to ensure you choose the correct assay for your study.

Cell viability assays assess how healthy the cells are by measuring markers of cellular activity. Cell viability determines how well or how poorly cells will respond to stress stimuli. Use cell viability assays when looking at the effect of pharmacological compounds on cells, optimizing cell culture conditions or ensuring optimal conditions of cells before starting experiments. In contrast, proliferation assays are used to monitor the growth rate of a cell population or to detect daughter cells in a growing population. Cytotoxicity assays are used to determine the number of live and dead cells in a population after treatment with a pharmacological substance.

Apoptosis assays look at how cells are dying by measuring markers that are activated upon cell death. These are specific biochemical and morphological markers that do not occur in necrosis. Use apoptosis assays when you want to examine how pharmacological compounds kill cells; or why some cells/tissues do not respond to toxic compounds. 

This table summarizes the most common assays that can be used to assess cell proliferation, cell viability, cytotoxicity and apoptosis: 

Assay typeCell proliferationCell viabilityCytotoxicityApoptosis
Annexin (PS exposure) assay


X
ATP & ADP determination assay
X

Caspase  activation assay


X
Cell cycle assayXX

Cell proliferation assayXX

Cell viability assayXX

DNA fragmentation (TUNEL) assay


X
Glutathione (GSH/GSSG) determination


X
LDH cytotoxicity assay
XX
Live-dead cell assay
XXX
Mitochondrial membrane potential assay


X
Non-caspase protease activation assay


X
Senescence assayX


Assessing cell culture health

Cell health can be assessed by looking at different parameters of viability or proliferation such as cytolysis, metabolic activity or senescence. Your choice of assay will depend on what you want to detect, what instrumentation is available and the type of sample you have.  Here we outline some of options available and what results you might expect:​​​

​​

Type of assayMechanism of actionMarkers/ dyesWhat to expect?Detection methodExample product
Cytolysis or membrane leakage assayWhen cell membranes are no longer intact, dyes can enter or escape the cell

- Propidium iodide (PI)

- 7-AAD

- DRAQ7™

- Trypan blue

Increased signal = dying cells

No signal = live cells

Flow cytometer

Microscopy

High content screening

Live and Dead Cell Assay ab115347

DRAQ7™​ ab109202

Cellular enzymes (LDH) are released into culture media when cellular membranes are compromisedLDH in intact cells

Increased signal = dying cells

No signal = live cells

Microplate reader

LDH Cytotoxicity Assay Kit II ab65393

​​LDH Cytotoxicity Assay Kit (Fluorometric) ab197004

Metabolic activity assayOxidation of a specific dye due to normal cellular (mitochondrial) metabolism (LDH, ATP)

- LDH in cell lysates

- MTT/XTT (resarzurin)

- WST-1

- Fluorescent dyes

Increased signal = live cells

Decreased signal = dead cells

Microplate  reader

Mitochondrial Viability Stain  ab129732

WST-1 Cell Proliferation Reagent (ready to use) ab155902

Cell cycle assaysFluorescent dye intercalates with DNA in intact cells

- PI

- DRAQ5™​​

- ​Nuclear Green CCS1

- Nuclear Red CCS1

Visualization of cell cyle phases: subG1 - G1 - S - G2/MFlow cytometer

Propidium Iodide Flow Cytometry Kit ab139418 

Cell Cycle Assay Kit (Fluorometric - Green) ab112116

Senescence assayDye that specifically stains cellular senescence markersSenescence - associated beta- galactosidaseBlue staining on senescent cells or tissue. Not visible on quiescent or immortal cellsImmunohisto-chemistry

Senescence Detection Kit ab65351

Download the full product list of assays to study cell viability and proliferation.

Cell viability assays assess how healthy the cells are, by measuring markers of cellular activity. Cell viability determines how well or how poorly cells will respond to stress stimuli. Use cell viability assays when looking at the effect of pharmacological compounds on cells, optimizing cell culture conditions or ensuring optimal conditions of cells before starting experiments. In contrast, proliferation assays are used to monitor the growth rate of a cell population or to detect daughter cells in a growing population. Cytotoxicity assays are used to determine the number of live and dead cells in a population e.g. after cells are treated with a pharmacological substance.
Apoptosis assays look at how cells are dying by measuring markers that are activated upon cell death. These are specific biochemical markers and morphological changes that do not occur in necrosis (which results in inflammation). Use apoptosis assays when you want to examine how pharmacological compounds kill cells; or why some cells/tissues do not respond to toxic compounds. 
There are a wide range of assays that can be used to assess cell viability and apoptosis; these are summarized below: Quantification of cellular proliferation can also help to determine optimal culture conditions as well as the cytotoxic effect that some treatment have on the overall cell population.

Cell viability, proliferation and apoptosis are generally seen together as complementary processes, and are not mutually exclusive. So it is important to understand what you are trying to detect or measure to ensure you choose the correct assay for your study.

Cell viability assays assess how healthy the cells are, by measuring markers of cellular activity. Cell viability determines how well or how poorly cells will respond to stress stimuli. Use cell viability assays when looking at the effect of pharmacological compounds on cells, optimizing cell culture conditions or ensuring optimal conditions of cells before starting experiments. In contrast, proliferation assays are used to monitor the growth rate of a cell population or to detect daughter cells in a growing population. Cytotoxicity assays are used to determine the number of live and dead cells in a population e.g. after cells are treated with a pharmacological substance.
Apoptosis assays look at how cells are dying by measuring markers that are activated upon cell death. These are specific biochemical markers and morphological changes that do not occur in necrosis (which results in inflammation). Use apoptosis assays when you want to examine how pharmacological compounds kill cells; or why some cells/tissues do not respond to toxic compounds. 
There are a wide range of assays that can be used to assess cell viability and apoptosis; these are summarized below: 
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