Affinity chromatography is a special type of chromatography used to separate and purify substances based on specific interactions between molecules.
How It Works:
- The stationary phase (like beads in a column) is coated with a molecule that specifically binds to the target substance.
- Example: An antibody, enzyme substrate, or receptor.
- The mixture is passed through the column.
- Only the substance that fits or binds to the stationary phase is retained.
- Other substances wash through the column without sticking.
- The target substance is then eluted (washed out) using a solution that breaks the binding.
Key Idea:
- Separation happens because of specific biological or chemical interactions, not just size, charge, or solubility.
- Only the molecule with the correct affinity will stick to the stationary phase.
Uses of Affinity Chromatography:
- Purifying proteins, enzymes, and antibodies.
- Isolating hormones or receptors.
- Studying protein-ligand or enzyme-substrate interactions in research.
In Short:
Affinity chromatography is a method that selectively separates a substance from a mixture by taking advantage of specific binding interactions.