Sodium Dodecyl Sulfate (SLS)

About This Product

Sodium dodecyl sulfate, SDS or sodium lauryl sulfate, has the formula C12H25NaO4S and CAS number 151-21-3. It is supplied as white needles, powder or paste, or as a 28 to 30 percent solution. Its role in biochemistry is worth understanding because it is a textbook example of surfactant behaviour put to analytical use. Proteins differ in shape and in net charge, so they cannot be separated by size alone in their native state. SDS unfolds them and binds along the polypeptide chain at a roughly constant ratio of about 1.4 grams per gram of protein, which swamps the protein's intrinsic charge with a uniform negative charge proportional to its length. Every protein in the sample then has effectively the same charge-to-mass ratio and a similar rod-like shape, so electrophoretic mobility depends only on molecular weight. That is the basis of SDS-PAGE, one of the most widely used techniques in the life sciences. Industrially the same strong, cheap detergency is used in cleaning products, in emulsion polymerisation as the surfactant that stabilises growing latex particles, and in foaming applications. It is used in laboratory electrophoresis and protein work, emulsion polymerisation, industrial and household cleaners, toothpaste and in mining flotation. Bio Green Chem supplies SDS in technical and analytical grades to specification on active matter, unsulphated matter, sodium sulfate, chloride, pH and colour.