SDS polyacrylamide-gel electrophoresis

SDS-polyacrylamide-gel electrophoresis is a technique used to seperate proteins by their net negative charge, molecular weight and shape. This is achieved through creating a gel containing cross-links of acrylamide subunits (polyacrylamide), which produces a matrix in which proteins can migrate through 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.Once an SDS-Page Gel electrophoresis has taken place, the fragments of DNA then need to be visualised. This can be done through a few different methods. One way is through UV imaging, another is through adding a dye to the DNA fragments.