What Is the Principle of MTT

1. What Is the Principle of MTT By Creative Animodel PD, PK, toxicology services provider

2. MTT Principle: • MTT is a method of detecting cell survival and growth (i.e. cell viability). • The principle of MTT experiment is to reduce exogenous MTT to water-insoluble blue-purple crystal formazan by succinate dehydrogenase in the mitochondria of living cells and deposit in cells, while metabolically de-active cells cannot. Dimethyl sulfoxide (DMSO) can dissolve the formazan in the cells, and its light absorption value can be measured with an enzyme-linked immunosorbent detector at a wavelength of 490 nm, which can indirectly reflect the number of active cells. • Within a certain range of cells, the amount of MTT crystal formation is directly proportional to the number of cells. The number of active cells is determined according to the measured absorbance value (OD value). The greater the OD value, the stronger the cells viability (unlike drug toxicity test).

4. MTT Applications: • This method has been widely used in the detection of activity of some biological activity factors, screening of large-scale anti-tumor drugs, cytotoxicity tests, and determination of tumor radio-sensitivity. • Advantages: it is characterized by its high sensitivity and economic features. • MTT is also commonly used for the determination of cell proliferation, cell viability and for the in vitro cytotoxicity test of drugs (including other treatments, for example radiation). • Disadvantages: Since the product of formazan produced from MTT is insoluble in water, it must be dissolved before it can be detected. This not only increases the workload, but also affects the accuracy of the experimental results. In addition, the organic solvents that dissolve the formazan is harmful to experimenters.

5. MTT Precautions: • In the preparation and preservation process, the container is best wrapped in aluminum foil. • MTT needs to be sterile protected since it is very sensitive to bacteria. • MTT is generally prepared by use. It can be stored at 4 centigrade in dark for 2 weeks or formulated into 5mg/ml and preserved for a long-term at -20 centigrade. Aliquot to avoid repeated freezing and thawing. It’s better to be packaged in small-dose, with dark bags or black paper, foil wrapped in dark to avoid decomposition. When MTT becomes grayish green, it cannot be used again. • MTT has carcinogenicity. Be careful when use. Precautions include wearing a transparent film glove.

6. MTT Precautions: • Typically, the MTT concentration in this method is 5 mg/ml. Therefore, 0.5g MTT can be weighed and dissolved in 100 ml phosphate buffered saline (PBS) or phenol red-free medium, filtered with a 0.22 μm filter to remove the bacteria in the solution, and stored at 4°C in dark. During the preparation and preservation process, the container is preferably wrapped in aluminum foil.

7. Related products: • Cell Viability and Cell Proliferation, MTT Assay • Reference: • Mosmann T. Rapid colorimetric assay for cellular growth and survival: Application to proliferation and cytotoxicity assays. J. Immunol. Meth. 1983;65:55–63. • Shum D, Radu C, Kim E, Cajuste M, Shao Y, Seshan VE, Djaballah H. A high density assay format for the detection of novel cytotoxic agents in large chemical libraries. J EnzInhib Med Chem. 2008;23(6):931–945. • Source: • https://www.creative-animodel.com/blog/what-is-the-principle-of-mtt/