SDS polyacrylamide-gel electrophoresis
SDS-polyacrylamide-gel electrophoresis is a technique used to separate proteins by their net negative charge, molecular weight and size. This is achieved through creating a gel containing cross-links of acrylamide subunits (polyacrylamide), which produces a matrix in which proteins can migrate towards the positive end when a electrical current is applied . Proteins which are smaller in size migrate through the gel faster and therefore travel further on the gel than those which are larger in size. This method can also be used for membrane proteins which are typically insoluble in water due to the separation occurring as a result of the size of the polypeptide chain. Dyes such as Coomassie Blue are used to stain and identify major proteins whereas silver or gold stain is used to highlight smaller proteins.
- ↑ Rath A, Glibowicka M, Nadeau VG, Chen G, Deber CM., Detergent binding explains anomalous SDS-PAGE migration of membrane proteins., 2009 Feb 10;106(6):1760-5. Available at: http://www.pnas.org/content/106/6/1760.full#aff-2
- ↑ Alberts,Bruce et al., 2008 Pg 517
- ↑ cell. 2006
- ↑ Alberts et al., Molecular Biology of the Cell, 2008, 5th Ed., Pg 517