MTT Assay

Definition

The MTT assay is a colorimetric assay used to measure cell viability, proliferation, and cytotoxicity. It is based on the ability of living cells to reduce the yellow MTT dye to a purple formazan product, which can then be quantified by measuring absorbance. This assay is significant in evaluating the effectiveness of biomaterials and drugs in both in vitro and in vivo testing.

5 Must Know Facts For Your Next Test

1. The MTT assay is widely used due to its simplicity and ability to provide rapid results regarding cell viability.
2. In the MTT assay, viable cells convert MTT into purple formazan crystals, which are insoluble and can be dissolved for spectrophotometric analysis.
3. The absorbance measured after dissolving formazan indicates the number of viable cells, making it a quantitative measure.
4. This assay can be applied to various cell types and is often used in drug development and toxicity testing of biomaterials.
5. The MTT assay is limited by factors such as interference from colored compounds and the potential for non-viable cells to produce false positive results.

Review Questions

• How does the MTT assay work to determine cell viability and what are its main components?
  • The MTT assay works by adding the yellow MTT dye to a culture of cells, where viable cells reduce it to purple formazan crystals. The main components include the MTT dye itself, which is taken up by living cells, and a solvent that dissolves the formed formazan product after incubation. By measuring the absorbance of the solution, researchers can determine the number of viable cells in the culture.
• Discuss the advantages and disadvantages of using the MTT assay in assessing cytotoxicity in biomaterials.
  • The MTT assay offers several advantages, such as being quick, easy to perform, and applicable to various cell types. It provides a reliable quantitative measure of cell viability, making it useful for evaluating cytotoxic effects of biomaterials. However, its disadvantages include potential interference from other substances present in samples that can affect color development, as well as limitations in distinguishing between live and dead cells if they are not fully lysed prior to measurement.
• Evaluate how the findings from an MTT assay can influence the development of new biomaterials or therapeutic agents.
  • Findings from an MTT assay can significantly influence biomaterial development by providing insights into cytotoxicity and cell compatibility. If a new biomaterial demonstrates low toxicity through high cell viability results in the MTT assay, it may progress toward further testing in vivo. Conversely, if high toxicity is observed, modifications may be needed before considering clinical applications. Thus, results from the MTT assay help inform both safety assessments and design strategies for effective therapeutic agents.

Related terms

Cytotoxicity: The quality of being toxic to cells, often used to assess the safety and effectiveness of materials or drugs.

Cell Proliferation: The process by which cells divide and reproduce, which is crucial for tissue growth and repair.

Colorimetric Assay: A laboratory technique that uses color change to quantify the concentration of analytes in a sample, often used for measuring cell activity.