MTT Assay

Definition

The MTT assay is a colorimetric technique used to assess cell viability and proliferation by measuring the metabolic activity of living cells. This method relies on the reduction of the yellow tetrazolium salt, MTT, into purple formazan crystals by mitochondrial enzymes in metabolically active cells, which can then be quantified. The assay is commonly used in tissue engineering and drug testing to evaluate the effects of various treatments on cell health and behavior.

5 Must Know Facts For Your Next Test

1. The MTT assay is based on the ability of viable cells to convert MTT into formazan, a process that only occurs in living cells due to their metabolic activity.
2. This assay can be performed in 96-well plates, allowing for high-throughput screening of multiple samples simultaneously, which is efficient for experimental setups.
3. Results from an MTT assay are quantitative and can provide insights into cell growth and cytotoxicity by measuring optical density using a spectrophotometer.
4. The MTT assay is sensitive to changes in cell morphology and behavior, making it a valuable tool in evaluating the effectiveness of tissue scaffolds in engineering applications.
5. Limitations of the MTT assay include interference from substances that may affect the optical density readings or that may be toxic to cells even if they do not affect metabolic activity.

Review Questions

• How does the MTT assay differentiate between viable and non-viable cells, and what implications does this have for assessing tissue engineering scaffolds?
  • The MTT assay differentiates between viable and non-viable cells by measuring metabolic activity; only living cells can reduce MTT to purple formazan crystals. This ability allows researchers to evaluate how effective different tissue engineering scaffolds are at supporting cell growth and viability. When testing scaffolds, a high level of formazan production indicates successful cellular interaction with the scaffold material, while low levels suggest poor performance or toxicity.
• Discuss how the MTT assay can be utilized to evaluate the cytotoxic effects of new biomaterials used in tissue engineering.
  • The MTT assay is essential for evaluating cytotoxicity by exposing cultured cells to new biomaterials and measuring changes in metabolic activity. If the material releases toxic substances or adversely affects cell function, a lower conversion of MTT to formazan will be observed. This quantitative data helps researchers ensure that new biomaterials are safe and supportive for potential applications in tissue engineering, ultimately guiding material selection.
• Analyze the advantages and limitations of using the MTT assay in evaluating treatments within the context of tissue engineering research.
  • The MTT assay offers significant advantages in tissue engineering research, including its ease of use, rapid results, and ability to analyze multiple samples simultaneously. However, it also has limitations; it does not provide information on cell morphology or viability if cells are metabolically inactive but still intact. Additionally, certain compounds can interfere with formazan formation or absorbance readings, potentially leading to inaccurate conclusions about cell health. Thus, while it is a valuable tool, it should be complemented with other assays for a comprehensive assessment.

Related terms

Cell Proliferation: The process by which cells divide and multiply, increasing in number, often measured to assess the growth and health of tissues.

Cytotoxicity: The quality of being toxic to cells; often assessed through various assays to determine the safety of drugs or other treatments.

Tissue Engineering: An interdisciplinary field that focuses on the development of biological substitutes that restore, maintain, or improve tissue function.