Sodium dodecyl sulfate or SDS, is an anionic surfactant (detergent) commonly used in research lab due to its multiple functions.
- The anionic detergent is capable of almost complete disruption of cellular structures by breaking non-covalent bonds and denaturing biomolecules, including proteins
- It facilitates the release of DNA from nuclei during genomic DNA extraction
- It solubilizes proteins in preparation for electrophoresis in SDS-PAGE
In SDS-PAGE the SDS works by masking the protein molecules native charge and imparts an associated negative charge to the protein molecules. This imparts an even distribution of charge per unit mass, resulting in a fractionation by approximate size during electrophoresis. - It is routinely used as a laboratory cleaner
SDS Stock Solutions
SDS stock solutions can be made in lab or premade solutions of SDS are available to reduce preparation time. There are however some factors to be wary of in case you are making or using a SDS stock solution or a solution containing SDS.
Sterile Solutions
If your SDS solution has to be sterile then it must be filtered through a 0.2-micron filter and not autoclaved. SDS during autoclaving will irreversibly precipitate and begins to hydrolyze to dodecanol and sulfuric acid. Hydrolysis of SDS results in the formation of dodecanol and the rate of this reaction is quite slow if stored at room temperature and neutral to weakly acidic pH, however autoclaving speeds up this procedure. A way to check the presence of dodecanol is to measure the surface tension of the solution, which will be lowered by the presence of dodecanol.
Storage Temperatures
SDS solutions should never be stored refrigerated. This can cause it to precipitate but if you warm it at 37°C it will go back into solution. Some of these problems can be avoided by simply using fresh solutions however you may store stock solutions of SDS at room temperature for use with a recommended minimum shelf life of 3 years.
