Figure 1. Elution of protein from an anion exchange column. Beads are shown in blue, protein in red; buffer ions are white circles. The protein is passed over the column and binds. Then an increasing salt gradient is passed over the column, displacing the protein.

Figure 2. The charge of a protein determines the type of ion exchange resin to be used.

Figure 3. Proteins eluting later from a gel filtration column become diluted. The figure shows an idealized chromatogram illustrating equimolar amounts of three proteins eluting at different times from a gel exclusion matrix. Note that the later peaks are broader and not as intense. Proteins eluting earlier show sharper peaks.