MTT Assays


The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay is a widely used colorimetric assay for measuring cell viability and proliferation in vitro. This assay relies on the conversion of MTT into a purple formazan dye by the mitochondrial enzyme, succinate dehydrogenase, in viable cells. The amount of formazan produced is proportional to the number of viable cells, which can be quantified by measuring the absorbance of the dye at a specific wavelength. The MTT assay is a simple, cheap, reliable, and sensitive technique that can be adapted to a wide range of experimental conditions and cell types. It is widely used in drug discovery, toxicology, and basic research to assess the cytotoxicity of compounds, evaluate cell growth and viability, and screen for potential anticancer agents. The MTT assay is also used in combination with other assays and techniques to gain a better understanding of cellular processes and signaling pathways.

Knowing how to perform an MTT assay is a powerful tool. In this tutorial, we will walk you through the theory, practice, and analysis of this assay. In addition, we showcase reagents necessary for the experiment along with downloadable protocols, planning, and analysis templates. Finally, we wrap it up with some real-world examples!


As discussed above, MTT assays are great for looking at cell viability and proliferation. In this brief video, we go over how these assays work and why they work. It's important to understand these things because they directly inform the limitations of this assay. The key takeaway here is that MTT assays are actually measuring metabolism and we estimate viability and proliferation based on that.

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Now that we understand the theory, let's talk about how to perform this assay. Below is a list of materials you will need.


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Let's go through some worked-out examples of different ways to set up this assay! We'll discuss a basic dose-response assay, and then further show the exact experimental setup, and finally discuss ways the setup can be expanded to accommodate multiple cell lines, drugs, etc.

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Antibodies are essential tools in biology and biomedical research, with a wide range of applications across different fields. These specialized proteins are produced by the immune system in response to the presence of foreign molecules, such as viruses, bacteria, or cancer cells. Once produced, antibodies can specifically bind to their target molecules, allowing researchers to detect, isolate, or even neutralize them. Antibodies have revolutionized many areas of biology, from basic research to drug discovery and clinical diagnostics.

In this tutorial, we will explore the basics of how antibodies are used and how they work. We will discuss the structure and function of antibodies and how they can be used in different experimental settings. Let's dive in!

Video Overview

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Antibodies have numerous applications. The video above describes the general principles of using antibodies for any of the relevant applications. Below are some of the things they can be used for.

  1. Immunodetection: Antibodies can be used to detect the presence of specific molecules in biological samples, such as proteins, DNA, or RNA. This technique, known as immunodetection, is widely used in research and clinical diagnostics, and can help identify biomarkers of disease or monitor the expression of genes or proteins in different tissues.
  2. Immunoprecipitation: Antibodies can also be used to isolate specific molecules from complex biological mixtures, such as cell lysates or serum. This technique, known as immunoprecipitation, allows researchers to study protein-protein interactions, identify novel protein complexes, or isolate specific proteins for further analysis.
  3. Flow cytometry: Antibodies can be conjugated to fluorescent dyes and used in flow cytometry, a technique that allows researchers to analyze and sort cells based on their surface markers. This approach is widely used in immunology and cancer research, and can help identify specific cell populations or characterize the immune response to different stimuli.
  4. Therapeutic applications: Antibodies can be used as therapeutics to treat a wide range of diseases, including cancer, autoimmune disorders, and infectious diseases. Monoclonal antibodies, which are produced from a single clone of immune cells, are particularly useful in this context, as they can be designed to specifically target disease-causing molecules while minimizing side effects.
  5. Antibody engineering: Advances in antibody engineering have enabled the development of novel antibody-based therapeutics with improved properties, such as increased specificity, affinity, or half-life. These engineered antibodies, also known as biologics, have revolutionized the field of drug development and have led to the development of several blockbuster drugs.

In summary, antibodies have become essential tools in biomedical research, with a wide range of applications across different fields. Their specificity, versatility, and ability to bind to specific molecules make them invaluable for studying biological processes, developing new diagnostic and therapeutic approaches, and advancing our understanding of human health and disease.

Understanding the principles described in the video will allow you to easily use antibodies across a range of applications, including western blotting, immunostaining, flow cytometry, live cell imaging, and much more.