TMB, free base

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Description

TMB Free Base (Molecular Biology Grade)

Chromogenic Substrate for Peroxidase / ELISA Detection

Product Overview

GoldBio’s TMB Free Base (3,3′,5,5′-Tetramethylbenzidine, free base) is a high-purity chromogenic substrate widely used for peroxidase-based detection in ELISA, Western blotting, and enzymatic assays.

Upon oxidation by horseradish peroxidase (HRP) in the presence of hydrogen peroxide, TMB produces a deep blue color that can be read directly or acid-stopped for yellow colorimetric quantification. This ≥98% pure, non-carcinogenic powder allows researchers to formulate custom detection substrates tailored to specific assay needs. Whether you're developing sensitive immunoassays or studying peroxidase enzyme kinetics, GoldBio’s TMB Free Base delivers reliable performance in a wide range of colorimetric applications. Because of its favorable safety profile compared to older substrates (e.g. benzidine), it is a preferred choice in many modern assays. 

Key Specifications & Identity

Property Value / Description
Synonyms / Alternate Names TMB, TMB Free Base
CAS Number 54827-17-7 
PubChem CID 41206 
Molecular Formula C₁₆H₂₀N₂
Molecular Weight ~240.35 g/mol
Grade Molecular Biology Grade 
Physical Form Solid powder / crystalline form 
Storage / Handling Store desiccated at 4 °C; protect from light 

Functional Highlights & Mechanism

  • TMB Free Base is a chromogenic electron donor that, when oxidized by HRP + H₂O₂, yields a blue-colored soluble product. 

  • The oxidized blue product absorbs at ~ 370 nm and ~ 652 nm. 

  • Addition of acid (e.g. sulfuric acid) halts the reaction, converting the blue product into a yellow derivative with peak absorbance at ~ 450 nm — suitable for stable endpoint measurements. 

  • Being a “free base” form (i.e. no additional salts or acidities), this substrate offers a purer baseline and may have more stable behavior in sensitive assays. 

  • It is commonly regarded as a safer (non-carcinogenic) alternative to older chromogens such as benzidine. 

Recommended Applications & Usage Notes

  1. ELISA / Immunoassays
    Use TMB Free Base in HRP-mediated ELISA reactions. After incubation, stop the reaction with acid and read the absorbance at 450 nm for quantification.

  2. Blotting / Membrane / Tissue Staining
    Can be applied in immunoblot or immunohistochemical protocols that utilize HRP, especially when a soluble colorimetric readout is suitable.

  3. Peroxidase / Hemoglobin Assays
    Useful in assays detecting peroxidase activity or hemoglobin (where heme peroxidase catalyzes oxidation of TMB).

  4. Kinetic & Endpoint Formats
    The soluble nature of the colored product means kinetic readings are feasible; alternatively, perform endpoint reads after acidification.

Usage Tips & Considerations:

  • Always protect TMB Free Base (solid and solutions) from light; it is photosensitive and may degrade over time. 

  • Prepare fresh working solutions and add hydrogen peroxide immediately before use to minimize background oxidation.

  • Include blank controls (substrate + buffer, no enzyme) to correct for baseline absorbance.

  • Ensure that the acid stop reagent is compatible with downstream plate reader optics and assay buffers.

  • Validate optimal incubation times and concentrations for your assay (common in 5–30 min range). 

Safety & Disclaimer

  • This product is intended for research use only — not for diagnostic or therapeutic use. 

  • Handle with care using appropriate laboratory safety practices (gloves, eye protection, avoid inhalation or ingestion).

  • Dispose of unused material and waste according to institutional and regulatory chemical safety procedures.

  • Consult the Safety Data Sheet (SDS) for detailed hazard, handling, and disposal information.

TMB, free base

View Sizes & Pricing

Catalog Number:
TMBF25
CAS Number:
54827-17-7
$1,063.00

For research use only. Not for food, drug, household, or cosmetic use.
Availability:
2-3 Weeks
Shipping:
$14.99 Ground shipping (In continental US only.)

    Description

    TMB Free Base (Molecular Biology Grade)

    Chromogenic Substrate for Peroxidase / ELISA Detection

    Product Overview

    GoldBio’s TMB Free Base (3,3′,5,5′-Tetramethylbenzidine, free base) is a high-purity chromogenic substrate widely used for peroxidase-based detection in ELISA, Western blotting, and enzymatic assays.

    Upon oxidation by horseradish peroxidase (HRP) in the presence of hydrogen peroxide, TMB produces a deep blue color that can be read directly or acid-stopped for yellow colorimetric quantification. This ≥98% pure, non-carcinogenic powder allows researchers to formulate custom detection substrates tailored to specific assay needs. Whether you're developing sensitive immunoassays or studying peroxidase enzyme kinetics, GoldBio’s TMB Free Base delivers reliable performance in a wide range of colorimetric applications. Because of its favorable safety profile compared to older substrates (e.g. benzidine), it is a preferred choice in many modern assays. 

    Key Specifications & Identity

    Property Value / Description
    Synonyms / Alternate Names TMB, TMB Free Base
    CAS Number 54827-17-7 
    PubChem CID 41206 
    Molecular Formula C₁₆H₂₀N₂
    Molecular Weight ~240.35 g/mol
    Grade Molecular Biology Grade 
    Physical Form Solid powder / crystalline form 
    Storage / Handling Store desiccated at 4 °C; protect from light 

    Functional Highlights & Mechanism

    • TMB Free Base is a chromogenic electron donor that, when oxidized by HRP + H₂O₂, yields a blue-colored soluble product. 

    • The oxidized blue product absorbs at ~ 370 nm and ~ 652 nm. 

    • Addition of acid (e.g. sulfuric acid) halts the reaction, converting the blue product into a yellow derivative with peak absorbance at ~ 450 nm — suitable for stable endpoint measurements. 

    • Being a “free base” form (i.e. no additional salts or acidities), this substrate offers a purer baseline and may have more stable behavior in sensitive assays. 

    • It is commonly regarded as a safer (non-carcinogenic) alternative to older chromogens such as benzidine. 

    Recommended Applications & Usage Notes

    1. ELISA / Immunoassays
      Use TMB Free Base in HRP-mediated ELISA reactions. After incubation, stop the reaction with acid and read the absorbance at 450 nm for quantification.

    2. Blotting / Membrane / Tissue Staining
      Can be applied in immunoblot or immunohistochemical protocols that utilize HRP, especially when a soluble colorimetric readout is suitable.

    3. Peroxidase / Hemoglobin Assays
      Useful in assays detecting peroxidase activity or hemoglobin (where heme peroxidase catalyzes oxidation of TMB).

    4. Kinetic & Endpoint Formats
      The soluble nature of the colored product means kinetic readings are feasible; alternatively, perform endpoint reads after acidification.

    Usage Tips & Considerations:

    • Always protect TMB Free Base (solid and solutions) from light; it is photosensitive and may degrade over time. 

    • Prepare fresh working solutions and add hydrogen peroxide immediately before use to minimize background oxidation.

    • Include blank controls (substrate + buffer, no enzyme) to correct for baseline absorbance.

    • Ensure that the acid stop reagent is compatible with downstream plate reader optics and assay buffers.

    • Validate optimal incubation times and concentrations for your assay (common in 5–30 min range). 

    Safety & Disclaimer

    • This product is intended for research use only — not for diagnostic or therapeutic use. 

    • Handle with care using appropriate laboratory safety practices (gloves, eye protection, avoid inhalation or ingestion).

    • Dispose of unused material and waste according to institutional and regulatory chemical safety procedures.

    • Consult the Safety Data Sheet (SDS) for detailed hazard, handling, and disposal information.

    Product Specifications

    Catalog ID: TMBF
    CAS #: 54827-17-7
    MW: 240.35 g/mol
    Grade: MOLECULAR BIOLOGY GRADE
    Storage/handling: Store desiccated at 4°C. Protect from light.
    PubChem Chemical ID: 41206
    IUPAC Name: 4-(4-amino-3,5-dimethylphenyl)-2,6-dimethylaniline
    InChI: InChI=1S/C16H20N2/c1-9-5-13(6-10(2)15(9)17)14-7-11(3)16(18)12(4)8-14/h5-8H,17-18H2,1-4H3
    InChIKey: UAIUNKRWKOVEES-UHFFFAOYSA-N
    SMILES: CC1=CC(=CC(=C1N)C)C2=CC(=C(C(=C2)C)N)C

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