Cell Health: Viability, Proliferation, Cytotoxicity, and Cellular Function

Cell viability, cell proliferation, and cytotoxicity assays

Cell viability assays measure various cell markers, such as ATP or metabolic enzyme activity, as indicators of cell health. Many assays for cell viability and cell proliferation, including a variety of cytotoxicity assays, are detected using microplate readers. Viability assays using different detection modes are available, each with its own advantages.

What is cell viability?

Cell viability refers to the number of healthy cells in a population and can be evaluated using assays that measure enzyme activity, cell membrane integrity, ATP production, and other indicators. These methods can employ luminescent, fluorescent, or colorimetric readouts as indicators of general cell viability or even specific cellular pathways. Cytotoxicity and cell viability assays are often used to assess a drug or other treatment’s effect and are valuable tools in the search for new therapeutics, as well as advancing our understanding of how normal cells function.


What is cell proliferation?

Cell proliferation refers to the overall increase in cell number and is vital for tissue growth. It is the result of both cell growth and cell division. Both processes are highly regulated in healthy organisms to balance cellular size and population size. In experimental setups, monitoring cell proliferation can give insights into the effects of drugs or other treatments on a population of cells.


Featured cellular health resources

  • Access cytotoxicity using the Delfia cell proliferation assay


    Cell proliferation is an important parameter to measure when testing compound toxicity or the effect of cytokines on a population of cells. Since cell proliferation requires the synthesis of DNA, one accurate way to measure cell proliferation is to monitor the uptake of the modified thymidine nucleotide BrdU1. The DELFIA® cell proliferation assay is a time-resolved immunoassay based on the incorporation of BrdU into newly synthesized DNA strands of proliferating cells.

    In this application note, we used the DELFIA cell proliferation assay to assess cytotoxicity of the chemotherapy drugs paclitaxel and etoposide in HeLa cells using the SpectraMax® i3 Multi-Mode Microplate Reader.

    Application note: Delfia cell proliferation assay on the SpectraMax i3 Multi-Mode Microplate Reader

    ATP-based cell viability assays

    ATP-based Cell Viability Assays

    Luminescent ATP assays for cell viability and cytotoxicity provide a sensitive and rapid way to measure the number of viable cells in culture and quantify the cytotoxic effects of experimental treatments. These assays can be done in a high-throughput format using SpectraMax® microplate readers.

    Learn about the CellTiter-Glo Luminescent Cell Viability Assay and more:

  • Colorimetric cell viability, cell proliferation, cytotoxicity assays (MTT, XTT, MTS)

    Cell Viability, Cell Proliferation, Cytotoxicity Assays

    Colorimetric assays using tetrazolium salts like MTT, XTT, and MTS can be used to measure cell proliferation and cytotoxicity. Enzymes present in viable cells reduce a chromogenic reagent to form a colored product that can be quantified by measuring the absorbance.

    Read the application note to learn about some of these methods:

    EarlyTox Cell Viability Assay Kits

    EarlyTox Cell Viability Assay Kits

    Cell viability assays are critical to a broad spectrum of research areas ranging from investigation into the mechanisms of cell death to the development of new therapeutics targeting apoptosis in diseases. One of the most popular detection technologies for cell viability is a fluorescence microplate reader.

    Here are a few applications you may find of interest:

  • Measure oxidative metabolism and glycolytic activity

    Measure oxidative metabolism and glycolytic activity

    To survive, cells require fuel in the form of ATP to carry out most essential bioprocesses. This fuel is generated through glycolysis and mitochondrial respiration. While both produce ATP, glycolysis can function in the absence of oxygen, whereas mitochondria require oxygen for the final step in oxidative phosphorylation (OXPHOS). Understanding how these pathways respond to effector compounds can provide useful insights into the overall function of cells and the underlying mechanisms that determine cell fate.

    Read our application note to learn about real-time data acquisition and analysis of the progression of oxygen consumption and glycolic activity:

    Measuring cell proliferation using the CyQUANT Kit

    Measuring cell proliferation using CyQUANT Kit

    Quantitation of cell proliferation using fluorescence allows one to easily monitor the effects of drugs and other experimental treatments on cell growth. The CyQUANT Cell Proliferation Assay Kit from Life Technologies is a sensitive, rapid and convenient way to quantitate cell growth using a fluorescence microplate reader.

    This application note describes how to use the CyQUANT kit with SpectraMax® Microplate Readers and SoftMax® Pro Software from Molecular Devices.

    Application note: Measuring cell proliferation using the CyQUANT Cell Proliferation Assay with SpectraMax Microplate Readers

  • Reactive Oxygen Species (ROS)

    Reactive Oxygen Species (ROS)

    Reactive Oxygen Species (ROS) are chemically reactive molecules containing oxygen. In eukaryotes, these molecules are mainly created during aerobic respiration and can cause problems, such as DNA damage and lipid peroxidation, resulting in cellular damage.  

    We demonstrate how SpectraMax microplate readers can be used to accurately quantify ROS levels using a luminescence-based assay:



    Toxicology is the study of adverse effects of natural or man-made chemicals on living organism. It is a growing concern in our world today as we are exposed to more and more chemicals, both in our environment and in the products we use.

    Read More 

Latest Resources

Resources of Cell health: Viability, proliferation, cytotoxicity, and cellular function