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DTNB  (Synonyms: Ellman’s Reagent)

Cat. No.: HY-15915 Purity: 98.26%
COA Handling Instructions

DTNB (Ellman’s Reagent) is a chemical used to quantify the number or concentration of thiol groups.

For research use only. We do not sell to patients.

DTNB Chemical Structure

DTNB Chemical Structure

CAS No. : 69-78-3

Size Price Stock Quantity
Free Sample (0.1 - 0.5 mg)   Apply Now  
Solid + Solvent
10 mM * 1 mL in DMSO
ready for reconstitution
USD 33 In-stock
Solution
10 mM * 1 mL in DMSO USD 33 In-stock
Solid
1 g USD 30 In-stock
5 g USD 65 In-stock
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Customer Review

Based on 3 publication(s) in Google Scholar

Top Publications Citing Use of Products
  • Biological Activity

  • Purity & Documentation

  • References

  • Customer Review

Description

DTNB (Ellman’s Reagent) is a chemical used to quantify the number or concentration of thiol groups[1].

In Vitro

DTNB reacts with the free sulfhydryl side chain of cysteine to form an S-S bond between the protein and a thionitrobenzoic acid (TNB) residue[1].
? The main advantage of DTNB over alternative reagents (e.g., N-ethylmaleimide or iodoacetamide) is in the selectivity of this reagent and in the ability to follow the course of the reaction spectrophotometrically[1].
? Modification of Enzyme with DTNB:
? Modification of the SH groups of the enzyme is carried out by reacting 10 μL of 10 mM DTNB solution (about a 20-fold molar excess) at room temperature with 0.6 mL of enzyme solution (0.807 mg/mL) in 80 mM phosphate buffer, pH 8.0, containing 1 mM EDTA, which has been dialyzed previously against the same buffer solution for 24 h. The number of SH groups is estimated from the increase of absorbance at 410 nm using a molar extinction coefficient of 13,600 M-1cm-1 for thionitrobenzoate ions liberated.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Molecular Weight

396.35

Formula

C14H8N2O8S2

CAS No.
Appearance

Solid

Color

Off-white to yellow

SMILES

O=C(O)C1=C([N+]([O-])=O)C=CC(SSC2=CC(C(O)=O)=C([N+]([O-])=O)C=C2)=C1

Shipping

Room temperature in continental US; may vary elsewhere.

Storage
Powder -20°C 3 years
4°C 2 years
In solvent -80°C 2 years
-20°C 1 year
Solvent & Solubility
In Vitro: 

DMSO : 100 mg/mL (252.30 mM; ultrasonic and warming and heat to 60°C; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

H2O : < 0.1 mg/mL (insoluble)

Preparing
Stock Solutions
Concentration Solvent Mass 1 mg 5 mg 10 mg
1 mM 2.5230 mL 12.6151 mL 25.2302 mL
5 mM 0.5046 mL 2.5230 mL 5.0460 mL
View the Complete Stock Solution Preparation Table

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

  • Molarity Calculator

  • Dilution Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Mass
=
Concentration
×
Volume
×
Molecular Weight *

Concentration (start) × Volume (start) = Concentration (final) × Volume (final)

This equation is commonly abbreviated as: C1V1 = C2V2

Concentration (start)

C1

×
Volume (start)

V1

=
Concentration (final)

C2

×
Volume (final)

V2

In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for in vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

  • Protocol 1

    Add each solvent one by one:  10% DMSO    40% PEG300    5% Tween-80    45% Saline

    Solubility: ≥ 2.08 mg/mL (5.25 mM); Clear solution

    This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).

    Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.

    Preparation of Saline: Dissolve 0.9 g sodium chloride in ddH₂O and dilute to 100 mL to obtain a clear Saline solution.
  • Protocol 2

    Add each solvent one by one:  10% DMSO    90% (20% SBE-β-CD in Saline)

    Solubility: ≥ 2.08 mg/mL (5.25 mM); Clear solution

    This protocol yields a clear solution of ≥ 2.08 mg/mL (saturation unknown).

    Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.

    Preparation of 20% SBE-β-CD in Saline (4°C, storage for one week): 2 g SBE-β-CD powder is dissolved in 10 mL Saline, completely dissolve until clear.
In Vivo Dissolution Calculator
Please enter the basic information of animal experiments:

Dosage

mg/kg

Animal weight
(per animal)

g

Dosing volume
(per animal)

μL

Number of animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.
Please enter your animal formula composition:
%
DMSO +
+
%
Tween-80 +
%
Saline
Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).
Calculation results:
Working solution concentration: mg/mL
Method for preparing stock solution: mg drug dissolved in μL  DMSO (Stock solution concentration: mg/mL).
The concentration of the stock solution you require exceeds the measured solubility. The following solution is for reference only. If necessary, please contact MedChemExpress (MCE).
Method for preparing in vivo working solution for animal experiments: Take μL DMSO stock solution, add μL . μL , mix evenly, next add μL Tween 80, mix evenly, then add μL Saline.
 If the continuous dosing period exceeds half a month, please choose this protocol carefully.
Please ensure that the stock solution in the first step is dissolved to a clear state, and add co-solvents in sequence. You can use ultrasonic heating (ultrasonic cleaner, recommended frequency 20-40 kHz), vortexing, etc. to assist dissolution.
Purity & Documentation

Purity: 98.35%

References

Complete Stock Solution Preparation Table

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Optional Solvent Concentration Solvent Mass 1 mg 5 mg 10 mg 25 mg
DMSO 1 mM 2.5230 mL 12.6151 mL 25.2302 mL 63.0756 mL
5 mM 0.5046 mL 2.5230 mL 5.0460 mL 12.6151 mL
10 mM 0.2523 mL 1.2615 mL 2.5230 mL 6.3076 mL
15 mM 0.1682 mL 0.8410 mL 1.6820 mL 4.2050 mL
20 mM 0.1262 mL 0.6308 mL 1.2615 mL 3.1538 mL
25 mM 0.1009 mL 0.5046 mL 1.0092 mL 2.5230 mL
30 mM 0.0841 mL 0.4205 mL 0.8410 mL 2.1025 mL
40 mM 0.0631 mL 0.3154 mL 0.6308 mL 1.5769 mL
50 mM 0.0505 mL 0.2523 mL 0.5046 mL 1.2615 mL
60 mM 0.0421 mL 0.2103 mL 0.4205 mL 1.0513 mL
80 mM 0.0315 mL 0.1577 mL 0.3154 mL 0.7884 mL
100 mM 0.0252 mL 0.1262 mL 0.2523 mL 0.6308 mL
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DTNB Related Classifications

Help & FAQs
  • Do most proteins show cross-species activity?

    Species cross-reactivity must be investigated individually for each product. Many human cytokines will produce a nice response in mouse cell lines, and many mouse proteins will show activity on human cells. Other proteins may have a lower specific activity when used in the opposite species.

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DTNB
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