TMB (3,3',5,5'-Tetramethylbenzidine) is a commonly used substrate in ELISA (Enzyme-Linked Immunosorbent Assay) because it produces a blue color when oxidized by the enzyme horseradish peroxidase (HRP). This color change is easily detectable and quantifiable, allowing researchers to measure the amount of target analyte present in a sample.
Here are some key reasons why TMB is a popular choice:
- High sensitivity: TMB exhibits a strong color change even at low concentrations of HRP, making it suitable for detecting trace amounts of analytes.
- Stability: TMB solutions are relatively stable, making them easy to store and use.
- Versatility: TMB can be used in various ELISA formats, including direct, indirect, and sandwich assays.
- Cost-effectiveness: TMB is generally affordable, making it a cost-effective substrate for ELISA.
In an ELISA, the HRP enzyme is attached to a secondary antibody that recognizes the target analyte bound to the plate. When the substrate TMB is added, it is oxidized by HRP, resulting in a blue color change. The intensity of the blue color is directly proportional to the amount of target analyte present in the sample. This allows researchers to quantify the analyte by comparing the color intensity to a standard curve.
TMB is a valuable tool in ELISA, providing a sensitive, reliable, and cost-effective method for detecting and quantifying target analytes.
