Trypan blue is an exclusion assay that will penetrate the dead cell membrane and bind ti its dna, while the mtt will be modified by the mitochondria of the living cells and test viability.  

I would like to see data generated via mtt assay, bc live dead will not help deduce viability.  Cells can be alive but not viable.  

CFSE also to test cellular proliferation, cell viability, and cytotoxicity are commonly used to monitor the response and health of cells in culture after treatment with various stimuli

Now a days i am doing the cell viability test heavily and usually MTT assay gives more higher accuracy as well as less hazardous to do. as trypan blue stains the dead cell but by The MTT assay is a colorimetric assay for assessing NAD(P)H-dependent cellular oxidoreductase enzymes activity of live cell.

Thank You very much everyone

MTT assay is a widely accepted and simple assay to determine cell proliferation for large number of samples. In some cases when the compound used for treatment interferes with the wavelength used for measurement of MTT. In that case, you may visually observe reduction in cells but the quantification will not match. It is then  you can think of alternative experiments. Therefore, doing MTT will be easier and accurate.

Thank You So Much!!!

Both these assays are acceptable. However I prefer the trypan blue test because it is much more informative due to the possibility to see directly and count the cells at the microscope. In fact, you can contemporary check the state of your culture for presence of contamination, drug precipitates or other problems e.g. normally you should not find dead cells in the control samples. This occurence could not be noted with the MTT test. Furthermore, looking at your samples, you can identify additional effects of the drugs you are testing such as alterations in cell volume, membrane damage, cell division and so on  that can fournish interesting information on how a drug actually produce its effects. However, in case of a large number of samples or when using adherent cell lines the MTT assay may be more feasible e.g. you won't need to use trypsin to detach the cells, a factor that can affect the precision of cell counting. Regards,

Thank You So Much!!!

A colorimetric assay based on MTT, XTT, MTS or WST-1 measures the enzymatic activity of mitochondrial dehydrogenase (succinate-tetrazolium reductase) that converts such tetrazolium salts into purple colored insoluble formazan. A similar assay employing resazurin or AlamarBlue can be used both colorimetrically and fluorometrically. The assay of this type evaluates the mitochondrial metabolism.

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A dye exclusion assay measures the membrane permeability and uses colorimetric (e.g., trypan blue, Erythrosin B) or fluorescent dyes (e.g., propidium iodide, ethydium bromide). In this assay, stained cells are considered non-viable suggesting the occurrence of cell death or other events leading to alterations in membrane permeabiliy.

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A colony formation or clonogenic assay measures the ability of single cells to form colonies with 50 or more cells, usually in about two weeks after plating. 

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For cell proliferation, in addition to methods listed above, the following methods are also useful. Tritiated thymidine uses radioisotope and evaluates the DNA synthesis. A similar assay employing other thymidine analogues BrdU, IdU, CldU or EdU does not need the use of radioisotope. There have been S phase markers available, such as Ki-67, PCNA, DNA topoisomerase II, and histone H3. Evaluation of E2F (required for a transition from G1 to S) or other proliferation-related markers may also be useful.

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If there is difference in cell proliferation, then flow cytometry may be conducted, followed by analyses of molecular changes in relation to cell cycle checkpoints. If sub-G1 fraction is increased, apoptosis will be checked. If you find a long term arrest, premature senescence will be checked. If a drug is a genotoxic agent, cytogenetic assays (e.g., chromosome aberrations and micronuclei) and mutation assays will also be useful.

As mentioned above, there are various methods but at different endpoints. Each method evaluates different aspect of cellular responses. For example, prematurely senescent cells are clonogenically inactive (do not form colonies), but are metabolically active and viable: thus, metabolic state and clonogenic potential are not necessarily the parallel events. So, the choice of the method depends on what you wish to look at.