Question

The most commonly used technique for separation of proteins is:

• A. Centrifugation
• B. Chromatography
• C. Filtration
• D. Precipitation

Hint:

Affinity chromatography is the most specific type of chromatography because it relies on unique biological interactions like antibody-antigen binding.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Downstream processing aims to isolate a target protein from a complex mixture of cells, nutrients, and other proteins. Separation techniques are chosen based on resolution and throughput.
Step 2: Detailed Explanation:
Chromatography is considered the "workhorse" of protein purification.
It allows for high-resolution separation based on various physical and chemical properties such as:
1. Charge (Ion-exchange chromatography).
2. Size (Size-exclusion chromatography).
3. Hydrophobicity (Hydrophobic interaction chromatography).
4. Binding specificity (Affinity chromatography).
- Centrifugation (Option A) and Filtration (Option C) are typically used for "clarification" (separating cells from liquid) rather than separating one specific protein from another.
- Precipitation (Option D) is used for bulk concentration but lacks the resolution of chromatography.
Step 3: Final Answer:
Chromatography is the most widely utilized and effective technique for the specific separation and purification of proteins.