In purifying proteins by column chromatography, elution can be performed in different ways, depending on the type of matrix. For example, bound proteins can be eluted by gradually increasing or decreasing salt concentration in the solution applied to the column. For which of the following matrices do you think increasing and decreasing salt concentration, respectively, are used for elution?
A) Ion-exchange; hydrophobic
B) Affinity; ion-exchange
C) Hydrophobic; affinity
D) Hydrophobic; ion-exchange
E) Ion-exchange; gel-filtration

Question

Quizplus · Accepted Answer

Increasing salt concentration would weaken the charge-charge interactions between bound proteins and an ion-exchange matrix. Decreasing salt concentration, on the other hand, weakens the hydrophobic interactions between bound proteins and a hydrophobic matrix.

In Purifying Proteins by Column Chromatography, Elution Can Be Performed