What is the MTT Assay?
The
MTT assay is a colorimetric assay for assessing cell metabolic activity. It is based on the reduction of the yellow tetrazolium MTT to purple formazan crystals by metabolically active cells. This assay is widely used to measure cell proliferation, cytotoxicity, and viability.
Cell Seeding: Cells are seeded into a 96-well plate and allowed to adhere and grow.
Treatment: Cells are treated with nanoparticles or other test substances.
MTT Addition: The MTT reagent is added, and cells are incubated to allow for metabolization.
Solubilization: Formazan crystals formed by viable cells are dissolved using a solubilizing agent (e.g., DMSO).
Measurement: The absorbance is measured using a spectrophotometer, which correlates with the number of viable cells.
Simplicity: The procedure is straightforward and does not require specialized equipment.
Quantitative: The assay provides quantitative data on cell viability.
Sensitivity: It is sensitive enough to detect small changes in cell viability.
Compatibility: The assay is compatible with a wide range of cell types and conditions.
Interference: Some nanoparticles can interfere with the assay by affecting the colorimetric readout.
Solubility Issues: Poor solubility of formazan crystals can lead to inaccurate results.
Endpoint Assay: It only provides a snapshot of cell viability at a specific time point.
These assays can provide complementary information and help to validate the results obtained from the MTT assay.
Conclusion
The MTT assay is a fundamental tool in nanotechnology for evaluating the cytotoxicity and biocompatibility of nanoparticles. While it is a robust and widely-used method, researchers must be aware of its limitations and consider complementary assays to obtain comprehensive data on nanoparticle interactions with biological systems.
