Size Exclusion Chromatography: Principle, Working, Applications, Advantages and Limitations
Size Exclusion Chromatography (SEC) is an important chromatographic technique used to separate molecules primarily according to their size and hydrodynamic volume. It is widely used in biotechnology, biochemistry, molecular biology, pharmaceutical research, and protein purification. Figure 1: Image showing how SEC works (AI-generated illustration for educational purposes) Unlike ion exchange chromatography, which separates molecules based on electrical charge, size exclusion Chromatography separates molecules according to their ability to enter pores within stationary-phase particles. Larger molecules are unable to enter some or all of the pores and so travel through the column more quickly, while smaller molecules enter more pores, follow a longer path through the column, and elute later. Size exclusion chromatography is particularly useful because of the usually low amount of binding between sample molecules and the stationary phase, making it a relatively gentle technique for se...
