Cells are plated in a 96-well plate and allowed to adhere and grow. MTT solution is added to each well and incubated to allow for formazan crystal formation. The medium is removed, and the crystals are dissolved in a solubilizing agent, typically DMSO. The absorbance is measured using a spectrophotometer at a wavelength of around 570 nm.
The absorbance correlates with the number of viable cells, allowing for the calculation of cell viability percentages.
