Sodium dodecyl sulfate (SDS), also known as sodium lauryl sulfate, is an anionic surfactant used in protein electrophoresis, protein solubilization, and other laboratory workflows requiring a strongly surface-active detergent. Its amphiphilic structure contains a hydrophobic C12 alkyl chain and a negatively charged sulfate head group.
Synonyms: SDS; Sodium lauryl sulfate; Sodium dodecyl sulphate; Dodecyl sulfate, sodium salt.
In protein analysis, SDS binds to polypeptides and disrupts noncovalent interactions, producing denatured protein-SDS complexes with a strong net negative charge. This behavior is central to SDS-polyacrylamide gel electrophoresis (SDS-PAGE), where proteins are separated primarily according to molecular size.
As an anionic surfactant, SDS is also used in polymer-particle and dispersion research, where adsorption at hydrophobic interfaces can reduce surface hydrophobicity and contribute to electrostatic stabilization.
Key Properties
- Anionic surfactant and detergent
- Chemical purity: ≥ 99.5%
- C12 content: ≥ 98.5%
- CAS Number: 151-21-3
- Molecular formula: C12H25NaO4S
- Molecular weight: 288.38 g/mol
- Structure: CH3(CH2)11OSO3Na
- Free fatty alcohol: < 0.2%
- Moisture: < 1.0%
- pH of 1% aqueous solution: 6.0–7.5
- O.D. of 3% aqueous solution at 230–350 nm: < 0.1 AU
- Water solubility: approximately 150 g/L at 20°C
- Melting point: 204–207°C
- Catalog number: 03945
- Package size: 1 kg
Applications
SDS-PAGE Protein Electrophoresis
SDS is widely used in denaturing polyacrylamide gel electrophoresis. Binding of SDS disrupts native protein structure and minimizes differences in intrinsic protein charge, allowing electrophoretic mobility to depend primarily on molecular size under appropriately controlled SDS-PAGE conditions.
Protein Denaturation & Solubilization
SDS is a strong ionic detergent used to disrupt noncovalent interactions and solubilize many proteins and protein-containing samples. The concentration and treatment conditions should be selected according to the protein system and the requirements of downstream analytical methods.
Polymer Particle & Dispersion Research
SDS is used as an anionic surfactant in polymer-particle systems. Adsorption at hydrophobic interfaces can reduce apparent surface hydrophobicity and contribute negative surface charge, supporting electrostatic stabilization of appropriate aqueous dispersions.
Compatibility & Bonding Considerations
- SDS is an amphiphilic small molecule, not a polymer
- The C12 hydrocarbon chain provides the hydrophobic portion of the molecule
- The sulfate group forms the hydrophilic, negatively charged head group in aqueous media
- Strong interactions with proteins make SDS effective for denaturation and solubilization but can also affect downstream protein structure and activity
- SDS concentration, ionic strength, temperature, and other solution components influence surfactant behavior
- Compatibility with downstream assays should be evaluated because residual detergent can interfere with some analytical methods
The combination of a hydrophobic dodecyl chain and an anionic sulfate head group accounts for the characteristic detergent and interfacial behavior of SDS. Its effects in protein, colloidal, and polymer systems depend on concentration and the composition of the surrounding solution.
Application Tips
- Prepare aqueous SDS solutions with clean laboratory-grade water and the concentration specified by the validated method
- Mix sufficiently to dissolve the detergent while limiting unnecessary foam generation
- For SDS-PAGE, maintain consistent SDS concentration and sample-treatment conditions across standards and unknowns
- Consider detergent compatibility with downstream protein assays, enzymatic measurements, chromatography, or other analytical procedures
- For polymer-particle or dispersion studies, optimize SDS concentration for the specific particle chemistry, solids content, ionic strength, and intended surface properties
Handling & Storage
- Store at room temperature in a cool, well-ventilated location
- Keep away from heat, sparks, open flames, and other ignition sources
- Avoid generating or inhaling dust during handling
- Avoid contact with skin and eyes
- Wear protective gloves, safety glasses, and suitable protective clothing
- Keep the container closed when not in use
Why Choose Polysciences?
Trusted by 6,000+ Researchers Worldwide
Cited in Thousands of Peer-Reviewed Studies
U.S. Manufacturing & Global Distribution
Reliable Delivery to 40+ Countries
FAQ
Click a question to expand.
1. What is SDS surfactant?
Sodium dodecyl sulfate (SDS) is an anionic surfactant composed of a hydrophobic 12-carbon alkyl chain and a negatively charged sulfate head group. This amphiphilic structure allows SDS to interact with hydrophobic surfaces and proteins while remaining dispersible in aqueous systems.
2. What is the chemical structure of sodium dodecyl sulfate?
SDS has the molecular formula C12H25NaO4S and can be represented as CH3(CH2)11OSO3Na. The dodecyl chain forms the hydrophobic portion of the molecule, while the sulfate group is the hydrophilic anionic head group.
3. Why is SDS used in SDS-PAGE?
SDS denatures proteins and forms negatively charged protein-detergent complexes. This reduces the influence of native protein charge and conformation so that electrophoretic separation in SDS-PAGE is governed primarily by molecular size.
4. Are sodium dodecyl sulfate and sodium lauryl sulfate the same compound?
Yes. Sodium dodecyl sulfate and sodium lauryl sulfate are names for the same compound, CAS Number 151-21-3. SDS and SLS are common abbreviations used in different laboratory and industrial contexts.
5. What are the specifications for Polysciences Cat. 03945?
Cat. 03945 is specified at ≥99.5% purity with ≥98.5% C12 content, <0.2% free fatty alcohol, <1.0% moisture, and a pH of 6.0–7.5 for a 1% aqueous solution. The optical density of a 3% aqueous solution from 230–350 nm is specified at <0.1 AU.
Safety & Documentation
Sodium dodecyl sulfate is classified as harmful if swallowed or in contact with skin and may cause an allergic skin reaction. The powder is also classified as a flammable solid. Avoid breathing dust, use appropriate laboratory ventilation, and wear protective gloves, eye protection, and suitable protective clothing. Refer to the product Safety Data Sheet (SDS) for complete handling, storage, first-aid, transport, and disposal guidance.
