Electrophoresis and gel staining

Electrophoresis and gel staining

  • Agarose gel electroporesis

    Agarose gel electrophoresis separates DNA fragments according to their size. Typically, a DNA molecule is digested with restriction enzymes, and the agarose gel electrophoresis is used as a diagnostic tool to visualize the fragments. An electric current is used to move the DNA molecules across an agarose gel, which is a polysaccharide matrix that functions as a sort of sieve to help "catch" the molecules as they are transported by the electric current.

  • SDS-PAGE Technique

    For proteins, sodium dodecyl sulfate (SDS) is an anionic detergent applied to protein sample to linearize proteins and to impart a negative charge to linearized proteins. This procedure is called SDS-PAGE.

  • SDS-PAGE gel staining

    Once protein bands have been separated by electrophoresis, they can be visualized using different methods of in-gel detection. The choice of staining technique depends on the availability of imaging equipment in the lab in many cases.

  • High Sensitivity Silver Stain for SDS-PAGE

    Sigma-Aldrich protocol for ProteoSilver™: High Sensitivity Silver Stain for SDS-PAGE

  • Imidazole–SDS–zinc reverse staining

  • Western blot

    The western blot (sometimes called the protein immunoblot) is a widely used analytical technique used to detect specific proteins in a sample of tissue homogenate or extract. It uses gel electrophoresis to separate native proteins by 3-D structure or denatured proteins by the length of the polypeptide. The proteins are then transferred to a membrane (typically nitrocellulose or PVDF), where they are stained with antibodies specific to the target protein.