affinity purification

Affinity purification is a technique used to isolate a specific molecule, such as a protein, from a mixture. It works by attaching a special tag to the target molecule—like a unique key—that binds strongly and selectively to a specific substance (the lock). When the mixture passes through a column containing this lock, the tagged molecules stick, while others wash away. Then, conditions are changed to detach and collect only the desired molecule. This method allows scientists to purify specific proteins efficiently for research or medical purposes.