What is 2-Mercaptoethanol (BME)?
2-Mercaptoethanol, also known as BME or β-mercaptoethanol, is a chemical compound with the formula HOCH₂CH₂SH. It is a clear, colorless liquid with a strong, unpleasant odor, commonly used as a reducing agent in biochemistry and molecular biology.
What is the chemical formula of 2-Mercaptoethanol?
The chemical formula of 2-Mercaptoethanol is HOCH₂CH₂SH.
What is the molar mass of 2-Mercaptoethanol?
The molar mass of 2-Mercaptoethanol is 78.13 g·mol⁻¹.
What are the physical properties of 2-Mercaptoethanol?
BME is a clear, colorless liquid with a density of 1.114 g/cm³, a melting point of −100 °C, a boiling point of 157 °C, and a refractive index of 1.4996. It has a distinctive, disagreeable odor.
What are the common uses of 2-Mercaptoethanol?
BME is used to break disulfide bonds in proteins for techniques like SDS-PAGE, to prevent oxidative damage in cell culture by scavenging oxygen radicals, and as a reducing agent in various biochemical applications.
What is the role of 2-Mercaptoethanol in protein analysis?
BME reduces disulfide bonds (S-S) in proteins to thiol groups (SH), disrupting tertiary and quaternary structures, which allows proteins to be fully denatured and separated by size in techniques like SDS-PAGE.
What concentration of 2-Mercaptoethanol is typically used in SDS-PAGE?
In SDS-PAGE sample buffers, BME is typically used at a 5% concentration.
What is the redox potential of 2-Mercaptoethanol?
The redox potential of BME is −0.26 V at pH 7.
What is the half-life of 2-Mercaptoethanol in solution?
The half-life of BME is greater than 100 hours at pH 6.5 and 4 hours at pH 8.5.
What are the safety considerations for handling 2-Mercaptoethanol?
BME is toxic and irritating to the skin, eyes, and respiratory tract. It should be handled in a well-ventilated fume hood with protective gloves and eye protection. Its lethal dose (LD50) is 244 mg/kg orally in rats.
What is the flash point of 2-Mercaptoethanol?
The flash point of BME is 68 °C (154 °F).
What is the explosive limit of 2-Mercaptoethanol?
The explosive limit of BME is 18%, indicating it can form explosive mixtures with air.
What are the alternatives to 2-Mercaptoethanol in biochemical applications?
Alternatives include dithiothreitol (DTT), tris(2-carboxyethyl)phosphine (TCEP), and glutathione. DTT is often preferred due to its stronger reducing power (−0.33 V) and lower toxicity.
What is the role of 2-Mercaptoethanol in cell culture?
BME is added to cell culture media (e.g., RPMI-1640) at concentrations like 50 mM to prevent toxic levels of oxygen radicals, protecting cells from oxidative damage.
What is the UN number for 2-Mercaptoethanol?
The UN number for BME is 2966, classifying it as a hazardous material for shipping.
What are the environmental impacts of 2-Mercaptoethanol?
BME is classified as Aquatic Acute 1 and Aquatic Chronic 2, meaning it can harm aquatic ecosystems. Proper disposal is required to minimize environmental impact.
What is the pKa of 2-Mercaptoethanol?
The pKa of BME is 9.643, indicating it is a weak acid.
What precautions should be taken when handling 2-Mercaptoethanol?
Wear protective gloves and eye protection, work in a fume hood, avoid skin and eye contact, and do not inhale vapors.
What is the method of manufacturing 2-Mercaptoethanol?
BME is industrially produced by reacting ethylene oxide with hydrogen sulfide, often catalyzed by thiodiglycol and zeolites.
What are the storage conditions for 2-Mercaptoethanol?
BME should be stored in a cool, dry place, away from oxidizing agents and acids, often under nitrogen to prevent oxidation.
What are the first aid measures for exposure to 2-Mercaptoethanol?
For skin contact, wash with soap and water; for eye contact, flush with water for 15 minutes; if inhaled, move to fresh air; if ingested, seek medical attention without inducing vomiting.
What is the role of 2-Mercaptoethanol in RNA extraction?
BME is used at 1-2% in lysis buffers during RNA extraction to inactivate RNases, protecting RNA from degradation.
What are the synonyms for 2-Mercaptoethanol?
Synonyms include 2-Sulfanylethan-1-ol, 2-Hydroxy-1-ethanethiol, Thioglycol, and β-Mercaptoethanol.
What is the significance of the hydroxyl group in 2-Mercaptoethanol?
The hydroxyl group reduces BME’s volatility and enhances its solubility in water, making it suitable for aqueous biochemical applications.
