MTT Assay: cell proliferation or cell viability??? - (Oct/12/2010 )

Hey there!

I have read some protocols about MTT assay and now I have a question: is it a Cell Proliferation assay or a Cell Viability assay??? In some protocols MTT is incubated for 4 hrs, in my opinion it's not enough to evaluate cell proliferation, then why they still calling "Proliferation Assay"? I mean, I understand why ³H-timidine incorporation assay is to evaluate cell proliferation, but to stain cells (like with trypan blue) is enough to say that is a valid cell proliferation assay? Or is it only a Cell viability assay???

Opinions will be appreciated.

Thanks a lot

Alexa

MTT assay is not able to measure cell proliferation or viability but it is a simple tool to estimate that characteristics.
MTT shows the level of cell methabolism ONLY.

To quantify cell viability and proliferation you have to use dyes (PI or 7-AAD), proliferation cell tracers (i.e. CFDA-SE) and prolifertion markers (i.e. KI-67).

Denis Baev on Tue Jan 25 13:54:40 2011 said:

I agree. MTT can not be used to quantify cell viability/proliferation. MTT is based on the ability of metabolically active cells to reduce the yellow tetrazolium salt (MTT) by to form insoluble purple formazan crystals, which are solubilized by the addition of a detergent and quantified (i.e color). It is an alternative to radiometric testing and is widely used in drug sensitivity, cytotoxicity studies.

More the viable cells, more will be the color after incubation (So we can say it is cell viability study) and when you do these at different time points and compare the values it will be like a cell proliferation study.

I can not afford to buy an ELISA reader and I would like to test my lymphocyte proliferation using trypan blue. Is what I can do.

I use MTT to measure relative cell viability compared to untreated samples for my cell viability assay. Having said that, I don't think you can use it for quantification, rather a relative means of comparison.
If you're using it to measure cell proliferation, i believe you'll have to incubate it for 4H with MTT prior to measuring at 570nm rather than limiting the assay to a mere 4H. So if you're assay is say 48H long, you pre-incubate with MTT at the 44H.