TMB in chemistry stands for 3,3′,5,5′-Tetramethylbenzidine.
This compound is a chromogenic substrate commonly used in various biological and chemical assays. Here's a more detailed breakdown:
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What it is: TMB is a white solid in its pure form. However, it's typically used in solution, often with ethyl acetate, where it appears as a pale blue-green liquid.
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Common Applications:
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ELISA (Enzyme-Linked Immunosorbent Assay): TMB is a popular visualizing reagent in ELISA. It reacts with the enzyme horseradish peroxidase (HRP), producing a colored product that can be measured spectrophotometrically. The intensity of the color is directly proportional to the amount of target molecule present.
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Immunohistochemistry (IHC): TMB is used as a chromogenic substrate for staining tissue sections. The reaction with an enzyme conjugate (like HRP) generates a visible deposit, allowing for the detection and localization of specific antigens within the tissue.
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Why it's used: TMB offers several advantages, including:
- High Sensitivity: It provides a strong signal even at low concentrations of the target molecule.
- Water Soluble: Easy to handle and use in aqueous solutions.
- Relatively Safe: Considered less hazardous compared to some other chromogenic substrates.
In summary, 3,3′,5,5′-Tetramethylbenzidine (TMB) is a valuable tool in biochemistry and immunology for detecting and quantifying specific molecules through colorimetric reactions.
