In the world of research chemicals, few compounds have earned as much cross-disciplinary respect as dimethyl sulphoxide DMSO. Known by its systematic name dimethyl sulphoxide and internationally catalogued under CAS No. 67-68-5 (also written as 67 68 5), this organosulfur solvent has become a staple across pharmaceutical labs, biotechnology research centres, industrial chemistry facilities, and academic institutions worldwide.
What makes dimethyl sulphoxide so uniquely valuable is not one defining trait, but a convergence of several: extraordinary solvent capability, remarkable biological membrane permeability, thermal stability, and the ability to function as both a carrier and a cryoprotectant. Whether you are running cell culture assays in a BSL-2 lab, formulating a new transdermal drug delivery system, or preserving stem cells for clinical use, dimethyl sulphoxide DMSO is almost certainly part of your workflow — or it should be.
This guide goes beyond the basics. We cover the full chemical identity of the compound, its molecular behaviour, its proven and emerging applications across industries, safe handling protocols, storage requirements, and what to look for when sourcing from a reliable Lab Chemicals Distributor Mumbai or any certified regional supplier in India.
Chemical Identity: What Is Dimethyl Sulphoxide?
Dimethyl sulphoxide (commonly abbreviated DMSO) is an organosulfur compound with the molecular formula (CH₃)₂SO. It belongs to the class of sulfoxides — compounds in which a sulfur atom is doubly bonded to an oxygen atom and singly bonded to two carbon groups.
Its unique chemical identity is registered and tracked globally under CAS No. 67-68-5 (67 68 5), which serves as the universal reference number used by chemists, regulators, procurement teams, and safety professionals worldwide when ordering, documenting, or classifying this substance. If you are sourcing dimethyl sulphoxide DMSO from any supplier — including a Lab Chemicals Distributor Mumbai — always verify that the product label and Certificate of Analysis (CoA) match CAS No. 67-68-5 to confirm identity and purity.
Physical and Chemical Properties
At room temperature, dimethyl sulphoxide is a colourless, odourless liquid with a slightly bitter taste. It has a melting point of 18.5°C, which means it solidifies just below room temperature in cooler lab environments — a practical consideration for storage. Its boiling point is 189°C, giving it a broad liquid-phase operating window.
Key physical data for CAS No. 67-68-5:
- Molecular weight: 78.13 g/mol
- Density: 1.1 g/cm³ at 20°C
- Flash point: 95°C (not highly flammable, but combustible)
- Refractive index: 1.479
- Vapour pressure: 0.42 mmHg at 20°C
- Miscibility: Fully miscible with water, ethanol, acetone, diethyl ether, chloroform, and most organic solvents
Dimethyl sulphoxide is highly polar and aprotic — meaning it carries a significant dipole moment but does not donate hydrogen bonds. This combination makes it one of the most powerful and universally applicable laboratory solvents known.
Why Polarity and Aprotic Nature Matter ?
Most solvents are either polar protic (like water and methanol, which donate hydrogen bonds) or nonpolar. Dimethyl sulphoxide DMSO occupies a rare and extremely useful middle ground: it is polar enough to dissolve ionic salts, charged molecules, and most pharmaceuticals, yet aprotic enough not to interfere with reactions sensitive to hydrogen bond donors. This is why it is the solvent of choice when researchers need to dissolve compounds that neither water nor standard organic solvents can handle alone.
Applications of Dimethyl Sulphoxide in Research and Industry
1. Pharmaceutical Research and Drug Development
The pharmaceutical industry is arguably the largest consumer of dimethyl sulphoxide DMSO globally. Its role here is multifaceted:
As a solvent for drug candidates: Many newly synthesised drug compounds particularly those discovered through high-throughput screening are poorly water-soluble. Dimethyl sulphoxide dissolves these compounds at high concentrations (typically 10–100 mM stock solutions), enabling them to be added to aqueous assay systems at low volumes. This is standard practice in drug discovery labs worldwide.
As a transdermal penetration enhancer: One of the most pharmacologically significant properties of dimethyl sulphoxide DMSO is its ability to penetrate biological membranes and carry dissolved compounds through the skin and into systemic circulation. This transdermal carrier function has been exploited in formulating topical anti-inflammatory products and is under active investigation for delivering analgesics, antifungals, and other active pharmaceutical ingredients (APIs) without injection.
As a cryoprotectant: When biological samples stem cells, red blood cells, sperm cells, embryos, or tissue biopsies are cryopreserved at ultra-low temperatures (typically −80°C to −196°C in liquid nitrogen), ice crystal formation destroys cellular structure. Dimethyl sulphoxide at concentrations of 5–10% v/v is the standard cryoprotective agent (CPA) used to prevent this damage. Its ability to penetrate cell membranes and suppress intracellular ice nucleation makes it irreplaceable in biobanking and transplant medicine.
Approved medical use — interstitial cystitis: The United States FDA approved dimethyl sulphoxide DMSO (as Rimso-50) for intravesical instillation in the treatment of interstitial cystitis, a chronic bladder condition. This marks one of the few direct clinical applications of a lab-grade chemical that has transitioned into therapeutic medicine.
2. Cell Biology and Biochemistry Research
In laboratory cell biology, dimethyl sulphoxide DMSO serves several critical roles beyond just dissolving compounds:
Inducing cellular differentiation: At concentrations of 1–2%, dimethyl sulphoxide induces differentiation in certain cell lines, most notably prompting erythroid differentiation in Friend murine erythroleukaemia cells. This property has made it a tool in cancer biology research and stem cell studies exploring lineage commitment.
DMSO stocks and assay preparation: The compound is used to prepare master stock solutions of test compounds in high-throughput screening (HTS) programmes. Acoustic dispensing systems transfer nanolitre volumes of dimethyl sulphoxide DMSO stocks into assay wells a process fundamental to modern drug discovery pipelines.
Protein crystallography: Dimethyl sulphoxide is used as a co-crystallisation solvent and cryoprotectant in X-ray crystallography, where protein crystals are cryo-cooled in solutions containing CAS No. 67-68-5 to prevent ice damage during data collection.
3. Industrial and Manufacturing Applications
Beyond the laboratory, dimethyl sulphoxide plays significant roles in industrial chemistry:
Polymer and resin processing: Its high solvency power and thermal stability make dimethyl sulphoxide DMSO effective for dissolving polymers particularly polyacrylonitrile (PAN), which is used in carbon fibre production. It is a key solvent in wet-spinning processes for synthetic fibre manufacturing.
Electronics manufacturing: In semiconductor fabrication, dimethyl sulphoxide is used in photoresist stripping the process of removing light-sensitive polymer coatings from silicon wafers after patterning. Its ability to swell and dissolve cured photoresist without attacking underlying metal layers makes it preferable to more aggressive solvents.
Paint stripping and surface preparation: Industrial formulations containing dimethyl sulphoxide DMSO are used for stripping epoxy coatings and industrial paints, particularly in aerospace and marine maintenance where substrate integrity is critical.
Chemical synthesis: As an aprotic polar solvent, dimethyl sulphoxide is used in a wide range of organic synthesis reactions Swern oxidations (converting primary alcohols to aldehydes), Pfitzner-Moffatt oxidations, and as a solvent medium for nucleophilic substitution reactions where reactant solubility in less polar solvents is problematic.
4. Agricultural Applications
The penetration-enhancing properties of dimethyl sulphoxide DMSO have found application in agriculture as well. When added to pesticide, herbicide, or foliar fertiliser formulations, it improves the delivery of active ingredients into plant tissue increasing uptake efficiency and potentially reducing the total chemical load required per application. Research continues into its utility as an adjuvant in precision agriculture.
5. Veterinary Medicine
Dimethyl sulphoxide DMSO is approved for veterinary use in several countries, primarily in topical formulations for horses and dogs to treat musculoskeletal inflammation, joint conditions, and localised swelling. Veterinary-grade DMSO gels and liquids are commonly stocked by equine practitioners. As with human use, application requires care due to the compound’s ability to carry contaminants transdermally.
Why CAS No. 67-68-5 Is a Critical Procurement Reference?
For procurement managers, laboratory managers, and quality control teams sourcing dimethyl sulphoxide in India or globally, the CAS No. 67-68-5 (67 68 5) is non-negotiable documentation. This Chemical Abstracts Service registry number uniquely identifies the substance, independent of trade names, brand variations, or regional naming conventions (e.g., “dimethyl sulphoxide” vs. “dimethyl sulfoxide” — same compound, different regional spelling).
When placing orders with any Lab Chemicals Distributor Mumbai or chemical supplier, the CoA for dimethyl sulphoxide DMSO should clearly state:
- CAS Number: 67-68-5
- Assay (purity): ≥99.5% for research-grade; ≥99.9% for pharmaceutical-grade
- Water content: ≤0.1% (critical — DMSO is hygroscopic)
- Appearance: Clear, colourless liquid, free from visible particulates
- Refractive index at 20°C: 1.478–1.480
Sourcing CAS No. 67-68-5 from a verified, ISO-certified distributor in Mumbai or across India ensures regulatory compliance, batch-to-batch consistency, and access to proper SDS documentation required for workplace safety and transport compliance.
Safety, Handling, and Storage of Dimethyl Sulphoxide DMSO
Toxicity Profile
Dimethyl sulphoxide has a well-established low acute toxicity profile in mammals. The oral LD50 in rats is approximately 14,500 mg/kg — comparable in order of magnitude to common table salt — making it one of the safest solvents used in laboratory settings from an acute oral exposure standpoint.
However, the characteristic that makes dimethyl sulphoxide DMSO so pharmaceutically interesting — its ability to penetrate biological membranes and carry dissolved substances — is also its primary safety concern in the lab. Any compound dissolved in DMSO can be rapidly transported through intact skin. This means that if your gloves, lab coat, or skin are contaminated with a solution of a toxic compound in dimethyl sulphoxide, your exposure is significantly amplified compared to a spill of the same compound in water.
Common side effects of skin contact with concentrated dimethyl sulphoxide include a garlic-like taste or odour in the breath (within minutes of skin contact), mild local warmth, and transient redness. These symptoms arise from metabolic conversion to dimethyl sulphide following absorption.
Personal Protective Equipment (PPE)
When working with CAS No. 67-68-5 in a research or industrial setting, the following PPE is recommended:
- Nitrile gloves (note: DMSO permeates standard latex and some nitrile gloves relatively quickly — use thick nitrile or laminated gloves for extended contact)
- Chemical splash goggles or safety glasses with side shields
- Lab coat or chemical-resistant apron
- Work in a well-ventilated area or fume hood when handling bulk quantities
Never handle dimethyl sulphoxide DMSO while wearing gloves that are also contaminated with other chemicals, as transdermal delivery of those chemicals will be accelerated dramatically.
Storage Requirements
Dimethyl sulphoxide (CAS 67 68 5) is hygroscopic — it absorbs water from the atmosphere readily, which dilutes purity and can affect assay results. Proper storage is essential:
- Store in tightly sealed, airtight containers — preferably amber glass
- Keep at 15–25°C, away from heat sources and direct sunlight
- Avoid freezing cycles — repeated freeze-thaw will degrade container seals
- Store away from strong oxidisers (concentrated nitric acid, peroxides) and strong reducing agents
- Shelf life for properly stored research-grade dimethyl sulphoxide DMSO is typically 2–3 years from manufacture
Single-use vials and ampoules (0.5 mL – 5 mL) are strongly recommended for compound stock solutions, to prevent repeated opening of bulk containers that causes water ingress over time.
Sourcing High-Purity Dimethyl Sulphoxide in India
India’s research and pharmaceutical manufacturing sectors represent one of the fastest-growing markets for high-purity research chemicals globally. Mumbai, as India’s commercial and industrial hub, hosts numerous chemical distributors — but quality, documentation standards, and supply chain reliability vary significantly.
When selecting a Lab Chemicals Distributor Mumbai for dimethyl sulphoxide DMSO (CAS No. 67-68-5), look for:
- ISO 9001 or GMP-certified procurement and distribution operations
- REACH-compliant documentation and full SDS availability
- Batch-specific Certificate of Analysis (CoA) with purity ≥99.5%
- Cold chain capability for temperature-sensitive grades
- Packaging options suited to lab scale (100 mL, 500 mL, 1 L, 2.5 L, and bulk)
- Transparent labelling that includes CAS No. 67-68-5 and IUPAC name
A reliable Lab Chemicals Distributor Mumbai supplying dimethyl sulphoxide will also be able to advise on waste disposal, regulatory classification under Indian Chemicals (Management and Safety) Rules, and transport compliance under ADR/IATA guidelines.
Dimethyl sulphoxide DMSO, registered under CAS No. 67-68-5 (67 68 5), is not simply a commodity solvent. It is a biochemically active, pharmacologically relevant, industrially versatile compound with a depth of application that few chemicals can match. From preserving stem cells for life-saving transplants to enabling the synthesis of next-generation pharmaceuticals, dimethyl sulphoxide sits at the crossroads of chemistry, biology, and medicine.
For research institutions, pharmaceutical companies, industrial manufacturers, and academic labs across India, sourcing high-purity dimethyl sulphoxide DMSO from a trusted Lab Chemicals Distributor Mumbai with proper documentation, verified CAS No. 67-68-5 certification, and consistent supply is not a procurement detail — it is a scientific necessity.
Invest in quality. Verify your CAS numbers. Work with certified distributors. And never underestimate what dimethyl sulphoxide brings to the bench.
