Method of the Month — Native PAGE

December 2020

Our method of the month for December is Native PAGE (polyacrylamide gel electrophoresis). This is a method used in lots of research that can separate proteins based on both their size and charge. If you hate reading, scroll to the bottom for a napkin sketch of the process. If you like words, here’s how it works:

The first step in any gel electrophoresis experiment (as you probably know) is to pipette your sample into a solid gel immersed in a buffer that can conduct electricity. Next, you run a current through the buffer (and by extension, the gel). The flow of electrons will gradually move your sample through the mesh-like structure of the gel, separating out the individual components into bands based on their unique characteristics. Since most protein samples look transparent to the human eye on their own, you have to tag your particular protein with some kind of dye to see it on the gel.

What makes Native PAGE unique is its ability to separate proteins based on the size, charge, and shape of their “native” structure. Many gel electrophoresis techniques use detergents like SDS, a common chemical in soap, to break down the 3D structure of the protein before running it through the gel, but Native PAGE does not. For many studies (like this one), maintaining the 3D structure of the proteins in question is essential. For example, using this technique as opposed to other forms of electrophoresis would allow you to distinguish between a fully assembled protein complex with multiple subunits and the unassembled subunits. This non-denaturing quality makes this technique incredibly valuable if you want to both preserve the complex structure of your proteins and separate them for analysis.