MES Monohydrate CAS No. 145224-94-8

Biological Buffering: Maintains stable pH in cell culture media (especially for plant cells and some bacteria) and protein-based buffer formulations

Protein Work: Used in protein purification via chromatography and as a running buffer in denaturing gel electrophoresis (e.g., SDS-PAGE) for separating small proteins

Metal Ion Studies: Suitable for solutions involving metal ions due to minimal affinity, avoiding interference

Biological Experiments: pH adjustment of plant culture media, reagent solutions, and physiological experiments

Nanotechnology: Participates in the synthesis of nanoparticles

Industrial Applications: Pharmaceutical-grade raw material with purity up to 99%

Primary Applications:

• Cell Culture Media: Buffers solutions in the slightly acidic pH range

• Protein Electrophoresis: Key component in running buffers for SDS-PAGE and other gel-based protein separation techniques

• Chromatography: Used as a buffer in ion-exchange and other forms of liquid chromatography for purifying proteins and nucleic acids

• Plant Cell Cultures: Particularly suitable for plant biology applications

• General Biochemistry: Standard buffer for enzymatic assays and reactions requiring a pH around 6.0

Chemical Formula: C₆H₁₅NO₅S (includes one molecule of water, C₆H₁₃NO₄S⋅H₂O)

Molecular Weight: 213.25 g/mol (for the monohydrate)

Nature: Zwitterionic compound with a protonated nitrogen in the morpholine ring and a negative charge on the sulfonate group

Classification: Member of the Good's buffers, designed for biological research

pKa: ≈6.1 at 25°C

Useful pH Range: 5.5−6.7

Appearance: White crystalline powder

Melting Point: >300°C (anhydrous form)

Solubility: Freely soluble in water (0.5 M solution)

Stability: Stable under normal conditions, incompatible with strong oxidizing agents

UV Transparency: Low absorbance in the ultraviolet range

Chemical Stability: Resistant to enzymatic and non-enzymatic degradation

Minimal Salt Effects: Properties not significantly altered by changes in ionic strength

Storage: Store in a dry, tightly sealed container

Residue Requirement: Residue on ignition <0.05%

Enzyme Activity Assay: Free of DNase/RNase/Protease contamination

Hazard Classification: Not considered hazardous by the 2012 OSHA Hazard Communication Standard (29 CFR 1910.1200)

First Aid Measures:

• Eye Contact: Rinse immediately with plenty of water, also under the eyelids, for at least 15 minutes. Get medical attention if symptoms persist.

• Skin Contact: Wash off immediately with plenty of water for at least 15 minutes. Get medical attention if symptoms persist.

• Inhalation: Remove to fresh air. Get medical attention if symptoms persist.

• Ingestion: Clean mouth with water and drink plenty of water afterward. Get medical attention if symptoms persist.

Fire-Fighting Measures:

• Suitable Extinguishing Media: Water spray, carbon dioxide (CO₂), dry chemical, alcohol-resistant foam

• Hazardous Combustion Products: Nitrogen oxides (NOₓ), carbon monoxide (CO), carbon dioxide (CO₂), sulfur oxides

Accidental Release Measures:

• Personal Precautions: Use personal protective equipment as required. Ensure adequate ventilation. Avoid dust formation.

• Environmental Precautions: Do not release into the environment. See Section 12 for additional Ecological Information.

• Methods for Containment and Clean Up: Sweep up and shovel into suitable containers for disposal. Avoid dust formation.

Handling and Storage:

• Handling: Wear personal protective equipment/face protection. Ensure adequate ventilation. Avoid ingestion and inhalation. Avoid contact with skin, eyes, or clothing. Avoid dust formation.

• Storage: Keep containers tightly closed in a dry, cool, and well-ventilated place. Incompatible materials: Strong oxidizing agents.