3,3',5,5'-Tetramethylbenzidine, 99%

Product Introduction

3,3',5,5'-Tetramethylbenzidine (TMB) is a widely used chromogenic substrate in biochemical and immunological assays. It is most commonly employed in enzyme-linked immunosorbent assays (ELISA) as a colorimetric substrate for horseradish peroxidase (HRP).

In the presence of HRP and hydrogen peroxide, TMB is oxidized to produce a blue-colored product, which can subsequently be converted to a yellow product after acid stop solution is added, enabling quantitative detection by spectrophotometry.

Due to its high sensitivity and reliable color development, TMB is extensively used in immunoassays, diagnostic reagent development, and biochemical detection systems.

Mechanism of Reaction

3,3',5,5'-Tetramethylbenzidine is an aromatic diamine compound that functions as a chromogenic peroxidase substrate.

In HRP-based detection systems:

• HRP catalyzes the oxidation of TMB in the presence of hydrogen peroxide
• Oxidized TMB forms a blue chromogenic product
• Addition of acid stop solution converts the color to yellow
• The absorbance of the final product is typically measured at 450 nm

The intensity of the color is proportional to the enzyme activity or analyte concentration in the assay.

Key Research Applications

1.ELISA Detection Systems

TMB is most commonly used as a chromogenic substrate in ELISA assays for HRP-labeled antibodies.Typical uses include:

• Antigen detection assays
• Antibody quantification
• Immunoassay signal generation
• Diagnostic ELISA kits

2.Immunohistochemistry and Immunoblotting

TMB can be used as a chromogenic reagent in HRP-based detection systems for protein analysis.Applications include:

• Western blot detection
• Immunohistochemical staining
• Enzyme-based signal visualization

3.Diagnostic Reagent Development

Due to its high sensitivity and stable color development, TMB is widely used in clinical diagnostic reagent research and IVD kit development.Applications include:

• Clinical ELISA kit development
• Biomarker detection assays
• Diagnostic immunoassays

4.Enzyme Activity Assays

TMB can be used to monitor peroxidase enzyme activity in biochemical experiments.Typical applications include:

• Peroxidase activity assays
• Enzyme kinetics research
• Oxidative enzyme detection systems

Recommended Experimental Conditions

Optimization may be required depending on the assay system.

Advantages in Enzyme Assays

• Highly sensitive chromogenic substrate for HRP
• Clear and stable color development
• Suitable for microplate-based assays
• Widely used in ELISA and diagnostic assays

Storage & Handling

• Store in a cool, dry, and dark place
• Protect from light to prevent oxidation
• Keep container tightly closed
• Follow recommended storage conditions for long-term stability

Related Applications

Researchers working with:

• ELISA detection systems
• HRP-based immunoassays
• Peroxidase activity assays
• Diagnostic immunoassay development

What is 3,3',5,5'-Tetramethylbenzidine used for?

• 3,3',5,5'-Tetramethylbenzidine is widely used as a chromogenic substrate for horseradish peroxidase (HRP) in ELISA and other immunoassays.

What wavelength is used to detect TMB reactions?

• The oxidized TMB product can be measured at 650 nm, while the acid-stopped yellow product is typically measured at 450 nm.

Why is TMB commonly used in ELISA assays?

• TMB provides high sensitivity, strong color development, and reliable spectrophotometric detection, making it ideal for ELISA and diagnostic assays.