MTT Assay

Definition

The MTT assay is a colorimetric assay used to assess cell viability by measuring the reduction of a yellow tetrazolium salt (MTT) to purple formazan crystals by metabolically active cells. This method is widely utilized in various fields, including regenerative medicine, to evaluate the health and proliferation of cells within bioprinted constructs, offering insights into the effectiveness of biomaterials and cellular responses.

5 Must Know Facts For Your Next Test

1. MTT stands for 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, which is converted by live cells into insoluble purple formazan crystals.
2. The intensity of the purple color produced correlates with the number of viable cells, allowing for quantification through spectrophotometry.
3. MTT assay is relatively simple and cost-effective, making it a popular choice for screening cell viability in various experimental settings.
4. It is important to optimize assay conditions, such as incubation time and cell density, to obtain accurate and reproducible results.
5. In regenerative medicine, MTT assays help evaluate how well bioprinted constructs support cell growth and function, guiding material selection and design.

Review Questions

• How does the MTT assay differentiate between viable and non-viable cells in bioprinted constructs?
  • The MTT assay differentiates between viable and non-viable cells based on metabolic activity. Viable cells reduce the yellow MTT tetrazolium salt to purple formazan crystals, while non-viable cells lack this activity. This makes the assay effective in determining the health of cells within bioprinted constructs, as it directly correlates with their ability to function and proliferate.
• Discuss the limitations of the MTT assay when evaluating cell viability in regenerative medicine applications.
  • While the MTT assay is widely used for assessing cell viability, it has limitations in regenerative medicine. For instance, it only measures metabolic activity rather than direct cell count or viability status, which may not accurately reflect the cellular response in complex bioprinted constructs. Additionally, certain materials used in bioprinting may interfere with the assay results, leading to false interpretations of cell health or toxicity.
• Evaluate how improvements in the MTT assay could enhance its application in assessing bioprinted tissue constructs.
  • Improvements in the MTT assay could enhance its application by incorporating more advanced detection methods or adjusting protocols to minimize interference from biomaterials. Developing a multi-parametric approach that combines MTT with other viability assays could provide a more comprehensive evaluation of cell health and function. Additionally, utilizing real-time monitoring techniques might allow researchers to observe dynamic changes in cell viability over time within bioprinted constructs, ultimately leading to better optimization of tissue engineering strategies.

Related terms

Cell Proliferation:

The process by which cells divide and increase in number, an important aspect to measure alongside cell viability in assays.

Bioprinting: A 3D printing technology that uses live cells and biomaterials to create tissue-like structures, which can be evaluated for cell viability using assays like MTT.

Cytotoxicity: The quality of being toxic to cells, which can be assessed through various assays, including the MTT assay, to determine the safety of materials or drugs.