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).