Dialysis: Diffusion Based Separation

Dialysis is a common technique used in biochemistry for separating molecules based on diffusion. In this procedure, a semipermeable membrane allows the movement of certain molecules based on size. This method can be applied to the removal of buffer, known as desalting, or exchanging buffer molecules or ions from a protein solution.

This video covers the principles of dialysis along with a general procedure.  Several applications of dialysis are reviewed, including the removal of gradient reagents following ultracentrifugation, removing detergent after a membrane protein extraction, and the reconstitution of proteins by changing the solution environment.