What are the methods used for protein desalting?

The three most widely used methods that can be used for protein desalting including gel filtration (molecular sieve chromatography), diafiltration, and ion exchange. 

• Gel Filtration stands out as the most efficient method for desalting protein solutions. In this method, a gel filtration matrix containing beads with varying pore sizes is employed to separate molecules based on their sizes. 
• In the Diafiltration method, the solution is passed through a filter with a specific pore size that retains salts while allowing other components to pass through. Complete desalting may require multiple steps. 
• In the Ion Exchange method, an ion exchange resin which serves as the stationary phase, facilitates the desalting of proteins.

Other protein desalting methods include dialysis, ultrafiltration, freeze drying, and high-performance liquid chromatography (HPLC).