Methyl red
Based on 1 Customer Validation
Methyl red is a pH-sensitive acid-base indicator and colorimetric reagent with a pKa of 5.1. Methyl red achieves visual judgment of the titration endpoint through reversible structural changes of protonation (red, pH < 4.4) and deprotonation (yellow, pH > 6.2). Methyl red is widely used in acid-base titration in chemical analysis and buffer pH monitoring in biochemistry.
For research use only. We do not sell to patients.
- Purity: 99.55%
- CAS No.: 493-52-7
- Formula: C15H15N3O2
- Molecular Weight:269.30
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Storage:
RT, protect from light.
In solvent -80°C, 1 year , -20°C, 6 months
Biological Activity
Methyl red is used as an acid-base indicator in titration experiments. When the pH changes from 4.4 to 6.2, the color of the solution changes from red to yellow, which can be used to determine the titration endpoint[1].
Methyl red can be dissolved in ethanol to make a 0.1% solution. A few drops are added to the solution to be tested. During the titration process, the color change is observed to determine the pH endpoint[1].
MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.
Chemical Information
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CAS No. 493-52-7
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Appearance Solid
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Molecular Weight 269.30
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Formula C15H15N3O2
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Color Purple to purplish red
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SMILES
O=C(C1=C(/N=N/C2=CC=C(N(C)C)C=C2)C=CC=C1)O
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Shipping
Room temperature in continental US; may vary elsewhere.
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Storage
RT, protect from light
In solvent -80°C 1 year -20°C 6 months
Solvent & Solubility
DMSO : 66.67 mg/mL (247.57 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)
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, 1 year; -20°C, 6 months. When stored at -80°C, please use it within 1 year. When stored at -20°C, please use it within 6 months.
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, 1 year; -20°C, 6 months. When stored at -80°C, please use it within 1 year. When stored at -20°C, please use it within 6 months.
Concentration (start) × Volume (start) = Concentration (final) × Volume (final)
Purity & Documentation
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Data Sheet (272 KB)
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SDS (252 KB)
- English - EN (252 KB)
- Français - FR (252 KB)
- Deutsch - DE (252 KB)
- Norwegian - NO (252 KB)
- Español - ES (252 KB)
- Swedish - SV (252 KB)
- Italian - IT (252 KB)
- Korean - KR (252 KB)
- Portuguese - PT (252 KB)
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Handling Instructions (2659 KB)
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, 1 year; -20°C, 6 months. When stored at -80°C, please use it within 1 year. When stored at -20°C, please use it within 6 months.
| Optional Solvent | Concentration Solvent Mass | 1 mg | 5 mg | 10 mg | 25 mg |
|---|---|---|---|---|---|
| DMSO | 1 mM | 3.7133 mL | 18.5667 mL | 37.1333 mL | 92.8333 mL |
| 5 mM | 0.7427 mL | 3.7133 mL | 7.4267 mL | 18.5667 mL | |
| 10 mM | 0.3713 mL | 1.8567 mL | 3.7133 mL | 9.2833 mL | |
| 15 mM | 0.2476 mL | 1.2378 mL | 2.4756 mL | 6.1889 mL | |
| 20 mM | 0.1857 mL | 0.9283 mL | 1.8567 mL | 4.6417 mL | |
| 25 mM | 0.1485 mL | 0.7427 mL | 1.4853 mL | 3.7133 mL | |
| 30 mM | 0.1238 mL | 0.6189 mL | 1.2378 mL | 3.0944 mL | |
| 40 mM | 0.0928 mL | 0.4642 mL | 0.9283 mL | 2.3208 mL | |
| 50 mM | 0.0743 mL | 0.3713 mL | 0.7427 mL | 1.8567 mL | |
| 60 mM | 0.0619 mL | 0.3094 mL | 0.6189 mL | 1.5472 mL | |
| 80 mM | 0.0464 mL | 0.2321 mL | 0.4642 mL | 1.1604 mL | |
| 100 mM | 0.0371 mL | 0.1857 mL | 0.3713 mL | 0.9283 mL |