GEL GILTRATION : Principles and Methods

Gel Filtration, also known as Size Exclusion Chromatography (SEC), is a technique used to separate molecules based on their size and, to some extent, their shape. The stationary phase consists of porous beads, typically made from materials like agarose or polyacrylamide. As a sample solution passes through the column, smaller molecules enter the pores and thus have a longer path, causing them to elute later. Larger molecules are excluded from the pores and travel a shorter, more direct path through the column, causing them to elute earlier. This method is non-destructive and does not rely on the chemical properties of the molecules, making it ideal for the separation and analysis of proteins, nucleic acids, polymers, and other macromolecules. Gel filtration is commonly used in biochemistry and molecular biology for desalting, buffer exchange, and determining the molecular weight and size distribution of molecules.