Chromatography is a widely used technique in laboratories for separating and purifying complex mixtures. Typically, the material used in chromatography media consists of particles or resin that are packed into a column. The sample is then inserted at the top of the column and flushed through with a liquid mobile phase, either by gravity or under pressure. Chromatography can be performed on a small scale for analytical purposes or on a medium-to-large scale for preparation and industrial applications.