Question

Which one of the following methods separates biomolecules based on their hydrodynamic volumes?

• A. Anion-exchange chromatography
• B. Cation-exchange chromatography
• C. Size-exclusion chromatography
• D. Thin-layer chromatography

Hint:

Size-exclusion chromatography is an effective method for separating large molecules from smaller ones based on size and volume. It is widely used for protein purification.

Answer 1

The Correct Option is C

Size-exclusion chromatography (also known as gel-filtration chromatography) separates biomolecules based on their size and hydrodynamic volume. In this technique, larger molecules elute first because they cannot enter the small pores in the stationary phase, whereas smaller molecules take longer to elute as they enter the pores. This makes size-exclusion chromatography the method that separates biomolecules based on their hydrodynamic volumes. Therefore, statement (C) is correct.
- (A): Anion-exchange chromatography separates biomolecules based on their charge by using a stationary phase that attracts negatively charged particles. This is not based on hydrodynamic volume. Hence, statement (A) is incorrect.
- (B): Cation-exchange chromatography works similarly to anion-exchange but attracts positively charged particles. It also does not separate based on hydrodynamic volume, so statement (B) is incorrect.
- (D): Thin-layer chromatography separates molecules based on their affinity for the stationary phase, not based on size or hydrodynamic volume. Therefore, statement (D) is incorrect.
Thus, the correct answer is (C).