You can also use Sulforhodamine B (SRB) for cell cytotoxicity assay. It has several advantages over MTT assay.

1. Some compounds interfere with MTT reduction with no effect on cell viability. This interference is absent using SRB.

2. Higher linearity compared to MTT.

3. It is based on cell density determination (measurement of cellular protein) unlike MTT which requires cellular metabolic activity to convert colourless tetrezolium to purple coloured formazan dye.

Thanks Amanda and Arnoud for input regarding Alamar blue(AB).

I have technical question , I had performed this assay yesterday . Added 10% AB to plates and read fluorescence at 560 /590 (excitation/emission wavelength) and absorbance at 570 nm (ref 600 nm). Fluorescence values were ok and proper differences were found with drug treatment . but absorbance values were very less (media control 0.1, experimental 0.5).and there was no differences were found with drug treatment. why? what should i consider ?

Hello,

Would you briefly explain the protocol you followed?

Seeded 10,000 cells/well in 96well plate. treated cells with drugs for 2days afterwards added 10% alamar blue incubated for 1-4hr and took reading as mentioned above.

You can also use Sulforhodamine B (SRB) for cell cytotoxicity assay. It has several advantages over MTT assay.

1. Some compounds interfere with MTT reduction with no effect on cell viability. This interference is absent using SRB.

2. Higher linearity compared to MTT.

3. It is based on cell density determination (measurement of cellular protein) unlike MTT which requires cellular metabolic activity to convert colourless tetrezolium to purple coloured formazan dye.