MTT Assay

Definition

The MTT assay is a colorimetric assay used to measure cellular viability and proliferation based on the ability of living cells to reduce the yellow MTT dye to a purple formazan product. This method is widely used in toxicology and pharmacology to assess cell health and response to different treatments, providing insights into dose-response relationships in cellular damage.

5 Must Know Facts For Your Next Test

1. The MTT assay is sensitive and can detect changes in cell viability at low concentrations of toxins or drugs.
2. In the MTT assay, viable cells convert MTT into formazan crystals, which can be dissolved in a solvent for quantification.
3. The intensity of the color produced is directly proportional to the number of living cells, allowing for the assessment of dose-response relationships.
4. MTT assays can be performed in various cell types and are adaptable for high-throughput screening applications.
5. While useful, the MTT assay does not differentiate between live and dead cells that may still retain metabolic activity, requiring careful interpretation of results.

Review Questions

• How does the MTT assay help in understanding dose-response relationships when studying cellular damage?
  • The MTT assay aids in understanding dose-response relationships by measuring how varying concentrations of a substance affect cell viability. When cells are exposed to different doses, the reduction of MTT to formazan reflects metabolic activity that correlates with cell health. Analyzing the resulting color intensity allows researchers to identify thresholds and the severity of damage at specific doses, highlighting crucial insights into how cells respond to stressors.
• Evaluate the limitations of the MTT assay in assessing cell viability, particularly in the context of determining deterministic effects.
  • While the MTT assay is widely used, it has limitations that affect its reliability in determining deterministic effects. For instance, it cannot distinguish between live cells that have impaired function and those that are genuinely dead. Additionally, some treatments might lead to temporary metabolic activity without improving overall cell health, potentially skewing results. Thus, while MTT can indicate toxicity levels, it may not fully capture all aspects of cellular response necessary for evaluating deterministic effects accurately.
• Synthesize information from the MTT assay's methodology and results interpretation to propose improvements for enhancing its reliability in radiobiological studies.
  • To enhance the reliability of the MTT assay in radiobiological studies, combining it with other methods like flow cytometry could provide a clearer picture of cell health. Flow cytometry can distinguish live from dead cells more effectively than MTT alone. Additionally, incorporating assays that measure apoptosis or necrosis alongside MTT would give more comprehensive insights into cellular responses. Implementing these combined approaches can lead to improved interpretation of dose-response relationships related to deterministic effects while addressing the assay's inherent limitations.

Related terms

Cell Viability: A measure of the proportion of live, healthy cells in a population, often assessed using various assays like MTT.

Foramzan: A purple crystalline product formed by the reduction of MTT dye, which indicates the metabolic activity of viable cells.

Deterministic Effects: Biological effects that increase in severity with increasing dose and have a threshold below which they do not occur, commonly related to radiation exposure.