Preparation of 20% (w/v) Sodium dodecyl sulfate (SDS) solution


  • Sodium dodecyl sulfate synonyms : SDS, Sodium laurilsulfate, Sodium lauryl sulfate, SLS
  • Linear formula : CH3(CH2)11OSO3Na
  • Molecular weight: 288.38 g/mole
  • CAS Number: 151-21-3
  • It is an anionic surfactant (detergent) and is used extensively in biological research as a strong protein denaturant and lipid-solubilizing agent.
  • It is also used extensively in our cleaning and personal care products, e.g., shampoos, hand soaps, bath products, shaving creams, toothpaste.
  • It appear as white to yellowish powder. It is soluble in water. Heating dissolves SDS quickly in water, thus helpful to prepare concentrated SDS aqueous solution (20% SDS solution in water). Once dissolved, SDS forms clear transparent or slight yellowish solution.
  • 10% or 20% (w/v) stock solution of Sodium dodecyl sulfate (SDS) is generally prepared in distilled water (or milli Q water). Stock solution can be used to prepare solutions.


  • Reagents
    • Sodium dodecyl sulfate (SDS)
    • Deionized / Milli-Q water
  • Equipment and disposable
    • Measuring cylinder
    • Conical flask / Beaker
    • Magnetic stirrer


20% Sodium dodecyl sulfate (SDS)


Preparation of 100 ml of 20 % Sodium dodecyl sulfate (SDS) in Deionized / Milli-Q water.


Step 1: To prepare 100 ml of 20% SDS solution, weigh out 20 grams SDS in 250 ml conical flask / beaker. Add 80 ml deionized / Milli-Q water and mix it.


  • One can use manual shaking using a glass pipette to mix the ingredients. Magnetic stirrer makes the dissolving process easy and convenient.


  • Do not dissolve in 100 ml of deionized / Milli-Q water. In most cases, solution volume increases when the large amount of solute is dissolved in solvent. see solution preparation
  • Wear face mask to avoid inhalation of SDS dust.
  • Try to avoid frothing. If you are using magnetic stirrer, keep the speed low to avoid frothing.

Step 2: Heat to 68 °C if necessary.


  • One can set the magnetic stirrer temperature 68 °C. If magnetic stirrer is unavailable, place the solution in a water bath set at 68 °C.


  • Make sure to dissolve any residual powder sticking to the glass.

Step 3: Adjust the volume to 100 ml with deionized / Milli-Q water. Mix it again.


  • Autoclaving is not required for 20% SDS solution.


  • Solution can be stored at room temperature for several months.


  • Do not store the solution at 4 °C. SDS will precipitate at at temperatures below 15 °C. If there is any precipitate, re-dissolve by warming the solution (68°C for 10 min)


  • Plasmid isolation by alkaline lysis method
  • SDS-PAGE electrophoresis
  • Preparation of Laemmli sample buffer
  • Stripping of immunoblot


To prepare Sodium dodecyl sulfate (SDS) solution of various volume (10 ml, 100 ml, 500 ml and 1,000 ml) and percentage (1%, 5%, 10% and 20%), follow the table.
Percentage (SDS solution) / Volume 10 ml 100 ml 500 ml 1000 ml
1% 0.1 g 1.00 g 5.00 g 10.00 g
5% 0.50 g 5.00 g 25.00 g 50.00 g
10% 1.00 g 10.00 g 50.00 g 100.00 g
20% 2.00 g 20.00 g 100.00 g 200.00 g