In protein analysis, what does size exclusion chromatography primarily achieve?

Size exclusion chromatography, also known as gel filtration chromatography, primarily achieves the isolation of proteins based on molecular weight. This technique utilizes a column packed with porous beads that allow smaller molecules to enter the pores, effectively elongating their path through the column. Conversely, larger molecules cannot enter the pores and thus pass through the column more quickly. This size-based separation enables the efficient fractionation of proteins, allowing researchers to isolate and purify them based on their size.

By focusing on molecular weight, size exclusion chromatography is particularly useful in applications such as removing smaller contaminants from a protein preparation or obtaining size distribution information for a protein sample. This technique does not rely on other properties such as pH or the chemical structure of proteins, which distinguishes it from other methods of protein analysis.