Which of the following is not a component of downstream processing

Options

A. Separation
B. Purification
C. Preservation
D. Expression

Answer

To determine which of the following is not a component of downstream processing, we first need to understand what downstream processing entails. Downstream processing is a crucial phase in biotechnology that involves the recovery and purification of biosynthetic products, typically after fermentation or cell culture processes.

### Step-by-Step Solution:

1. **Understand Downstream Processing**: Downstream processing consists of several stages that occur after the production of biological products. The main components include:
- **Separation**: This is the initial step where the desired product is separated from the biomass and other impurities.
- **Purification**: After separation, the next step is to purify the product to remove any remaining contaminants and ensure that the product is safe and effective for use.
- **Preservation**: Finally, the purified product is preserved to maintain its stability and efficacy for storage and distribution.

2. **Identify the Options**: The question provides several options. We need to analyze each option to see which one does not fit into the downstream processing category.
- **Option 1: Separation** - This is a key component of downstream processing.
- **Option 2: Purification** - This is also a fundamental part of downstream processing.
- **Option 3: Preservation** - This is the final step in downstream processing.
- **Option 4: Expression** - This term typically refers to the process of producing a protein or gene product in a host organism, which is part of upstream processing, not downstream.

3. **Conclusion**: Based on the analysis, the correct answer is **Option 4: Expression**, as it is not a component of downstream processing.

### Final Answer:
The component that is not part of downstream processing is **Expression**.