Method of the Month: Protein Column Chromatography
This month’s method of the month is focused on column chromatography, a useful tool to purify proteins in the lab.
Column chromatography is a popular method used in both biology and chemistry to isolate pure solutions of specific molecules or proteins based on their differences in size, polarity, charge, or shape. Protein column chromatography works by running a solution of mixed proteins and a solvent (called the eluent) through a hollow tube filled with a solid stationary phase. This process (called elution) allows the mixture of proteins to interact with the molecules of the stationary phase slowly.
The stationary phase in protein column chromatography purifications is traditionally silica or alumina, a polar compound which easily attracts other polar or charged molecules. The eluent fluid usually is less polar than the stationary phase. Because of this dynamic, proteins that are more charged and have more hydrophilic sites are more attracted to the stationary phase, and elute out of the column later than proteins that have less charge and are more attracted to the mobile phase.
Biologists collect the mobile phase in small fractions as it exits from the column. These fractions allow samples of multiple proteins to be isolated into solutions of individual proteins based on their differences in size, charge, and polarity. Multiple rounds of column chromatography can be used to separate similar proteins or for pharmaceutical applications requiring high purity.
For more information on applications and procedures of protein column chromatography, check out these resources:
https://www.sciencedirect.com/science/article/abs/pii/S0065323308604222?via%3Dihub
