The Protein Man's Blog | A Discussion of Protein Research

Non-Radioactive Assays for Cell Toxicity and Cell Proliferation Determination

Posted by The Protein Man on Dec 18, 2012 5:00:00 AM
The Protein Man

Question:

Which non-radioactive assays are used to determine cell cytotoxicity and cell proliferation?  

The Protein Man Says:

While there are a number of non-radioactive assays that can help determine cell proliferation and viability as well as cell toxicity, determining the most appropriate assay to use can be very vital in obtaining the right information from the given cell sample. So, how do you know which one to use in each particular case? Here is a guide that can help you accomplish this task.

cell cytoxicity, cell proliferation, non radioactive assaysMeasuring Cell Viability, Proliferation and Cytotoxicity

Cell viability and cytoxicity assays are best used in determining the metabolic and proliferative activities of cells within a given sample. As such, they can be used to obtain vital information on the effects of certain experimental stimulus on the proliferation of cells within an in vitro environment.

There are a number of ways by which you can get an accurate indication of the cell vitality within your sample. You can choose to assess plasma membrane integrity, mitochondrial activity and/or metabolic activity to accomplish your purpose.

Membrane integrity can be assessed by monitoring the passage of LDH to the extracellular environment. Since LDH is normally confined inside the cell, its presence in the extracellular environment indicates loss of cell membrane integrity, an occurrence that usually follows apoptosis or necrosis. If you want to measure the amount of LDH in your sample, consider using CytoScan LDH Cytotoxicity and Cytoscan Fluoro Cytotoxoicity Assays.

On the other hand, you may want to use Cytoscan WST-1 Cell Proliferation Assay if you are interested in determining cell cycle regulatory factors. This particular colorimetric assay works on the basic principle that tetrazolium salt WST-1 will be reduced to water-soluble formazan by the action of cellular dehydrogenases. The resulting formazan dye can then be accurately measured by absorbance.  

For cell density determination, you can use the Cytoscan SRB Cytotoxicity Assay. This particular assay is based on the quantitative staining of cells with the fluorescent dye Sulforhodamine B, an anionic aminoxanthene dye that forms an electrostatic complex with the basic amino acid residues of proteins under moderately acid conditions. This reaction provides a sensitive linear response that can be readily measured at absorbances between 560 and 580 mm. This method is regarded to be a highly efficient and cost-effective method for screening and has a sensitivity that is comparable to those using fluorimetric methods.

In summary, here are the specific uses and properties of the different cell viability and cytoxicity assays:

CytoScan LDH Cytotoxicity Assay

  • Colorimetric assay used in measuring amount of LDH in the sample

Cytoscan Fluoro Cytotoxoicity Assay

  • Fluorometric assay used in measuring amount of LDH in the sample

  • Assays performed directly in cell culture wells

Cytoscan WST-1 Cell Proliferation Assay

  • Colorimetric assay used in determining cell cycle regulatory factors

  • Uses WST-1, a high sensitivity tetrazolium salt

  • Requires no washing, harvesting or solubilization

Cytoscan SRB Cytotoxicity Assay

  • For cell density (biomass) determination

  • Linear response

  • Simple, accurate and reproducible assay

 

Image By: Libertas Academica

Topics: Cytotoxicity Assays

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CB™ PROTEIN ASSAY: A Bradford Protein Assay

CB Protein Assay Graph

An improved Coomassie Dye based protein assay based on the Bradford Protein Assay. This assay is suitable for the simple and rapid estimation of protein concentration. This assay is based on a single Coomassie dye based reagent. The binding of protein to the dye results in a change of color from brown to blue. The change in color density is proportional to protein concentration. Protein estimation can be performed using as little as 0.5µg protein.

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