The following separation technique depends on the molecular size of protein:
**Core Concept**
The question is testing the understanding of various protein separation techniques based on their molecular properties. The correct answer is related to a method that separates proteins based on their molecular size, which is crucial in biochemistry and molecular biology.
**Why the Correct Answer is Right**
The correct answer is **Sedimentation** (or **Ultracentrifugation**), which separates proteins based on their size and density. During sedimentation, a centrifugal force is applied to the protein mixture, causing the proteins to separate based on their molecular weight. Proteins with higher molecular weight sediment faster and are found at the bottom of the centrifuge tube, while smaller proteins remain at the top. This technique is widely used in biochemistry and molecular biology to separate and purify proteins.
**Why Each Wrong Option is Incorrect**
* **Option A:** Gel Filtration (or Size Exclusion Chromatography) separates proteins based on their size, but it is not the correct answer because sedimentation is a more specific technique that separates proteins based on both size and density.
* **Option B:** Ion Exchange Chromatography separates proteins based on their charge, not size, so it is not the correct answer.
* **Option C:** Affinity Chromatography separates proteins based on their specific binding to a ligand, not size, so it is not the correct answer.
**Clinical Pearl / High-Yield Fact**
Remember that sedimentation is a critical technique in biochemistry and molecular biology for separating and purifying proteins based on their size and density.
**Correct Answer:** C.