The process of separation and purification of expressed protein before marketing is called

Options

A. Upstream processing
B. Downstream processing
C. Bioprocessing
D. Postproduction processing

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term used to describe the process of separating and purifying expressed proteins before they are marketed.

2. **Identifying the Process**: In biotechnology, after proteins are expressed (produced), they need to undergo a series of steps to ensure they are pure and suitable for use or sale.

3. **Defining Downstream Processing**: The process that encompasses the separation and purification of expressed proteins is known as "downstream processing." This term refers to all the steps involved after the fermentation or expression of the protein, which includes recovery and purification.

4. **Components of Downstream Processing**:
- **Removal of Insoluble Materials**: The first step involves removing any insoluble materials that may have formed during the expression of the protein.
- **Isolation of the Product**: Next, the desired protein is isolated from the mixture.
- **Purification of the Product**: After isolation, the protein undergoes purification to remove any contaminants.
- **Product Polishing**: Finally, the product is polished to ensure it meets the required standards before marketing.

5. **Conclusion**: After completing these processes, the purified protein is ready for marketing. Therefore, the correct answer to the question is "downstream processing."

**Final Answer**: The process of separation and purification of expressed protein before marketing is called **downstream processing**.

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