Cell Viability Assay Protocols

GUIDELINE

Cell viability is defined as the number of healthy cells in a sample. The measurement of cell viability plays an important role in all forms of cell culture. Sometimes it is the main purpose of the experiment as in toxicity assays, or it can be used to correlate cell behavior to the number of cells. Researchers apply various types of assays to screen the outcome of developing therapeutics that often target cancer cells.

METHODS

MTT assay protocol

  • Discard media from cell cultures. For adherent cells, carefully aspirate the media. For suspension cells, spin the 96 well plates at 1000 x g, 4°C for 5 minutes in a microplate-compatible centrifuge and carefully aspirate the media. An alternative method is to add an equal volume of MTT solution to the existing media in the culture. Ensure that the same volume of existing media is present for each sample.
  • Add 50 µL of serum-free media and 50 µL of MTT solution into each well.
  • Incubate the plate at 37°C for 3 hours.
  • After incubation, add 150 µL of MTT solvent into each well.
  • Wrap the plate in foil and shake on an orbital shaker for 15 minutes. Occasionally, pipetting of the liquid may be required to fully dissolve the MTT formazan.
  • Read absorbance at OD=590 nm. Read the plate within 1 hour.

WST-8 protocol

  • Cell suspensions seeded to 96-well plates (100 µl/well) with or without the test compounds are incubated at 37°C in a humidified incubator with 5% CO2 for the required exposure time.
  • 10 µL of WST-8 reagent solution is added to each well and the plate is incubated at 37°C for 2 hr. After incubation, the absorbance is measured at 450 nm with a multi-plate reader.

MTS assay protocol

  • Prepare cells and test compounds in 96-well plates containing a final volume of 100 µl/well. An optional set of wells can be prepared with medium only for background subtraction.
  • Incubate for a desired period of exposure.
  • Add 20 µl MTS solution containing PES to each well (the final concentration of MTS will be 0.33 mg/ml).
  • Incubate for 1-4 hours at 37°C.
  • Record absorbance at 490 nm.

Creative Bioarray Relevant Recommendations

NOTES

  • Using a tightly controlled and consistent source of cells to set up experiments.
  • Performing appropriate characterization of reagent concentration and incubation time for each experimental model system.

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