Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) is the most desirable method used for the qualitative analysis of the protein mixtures. This method is basically used for checking purity of the proteins. Since, in SDS-PAGE the proteins get separated in accordance to their size, the method is also used to determine the molecular weight of the proteins. After performing the SDS-PAGE, subsequent specialized techniques such as Western blotting, two-dimensional gel electrophoresis and peptide mapping can be done.
With the help of SDS-PAGE, a wide range of proteins can be separated by preparing varying concentrations of polyacrylamide gels. Generally, 10% polyacrylamide concentration of gel is sufficient enough to resolve the proteins ranging from 10-150kDa.