Objective: This session provides a foundational understanding of core separation techniques essential for isolating, purifying, and analyzing biological molecules (proteins, nucleic acids, metabolites) in biotechnological applications.
1. Introduction to Downstream Processing
Separation is a critical stage in downstream processing, occurring after fermentation or cell culture. Its goal is to isolate a target product from a complex mixture containing cells, debris, contaminants, and undesired metabolites. Efficiency and purity are key objectives.
2. Key Principles in Practice
- Resolution and Purity: The effectiveness of a technique is measured by its ability to resolve the target from impurities.
- Sequential Purification: Often, multiple techniques are combined (e.g., precipitation → IEX → SEC) to achieve high purity.
- Scale: Methods vary between analytical (µg-scale, for analysis) and preparative (mg-to-g-scale, for production).
3. Applications in Biotechnology
- Pharmaceuticals: Purification of recombinant proteins, vaccines, and antibodies.
- Diagnostics: Isolation of DNA for PCR, proteins for immunoassays.
- Food & Environment: Analysis of toxins, allergens; recovery of enzymes.
4. Challenges and Considerations
- Yield vs. Purity: Optimizing the balance between product recovery and purity.
- Cost: Downstream processing can account for up to 80% of total production costs.
- Scalability: Techniques must be adaptable from lab to industrial scale.
Conclusion: Mastery of these separation techniques is fundamental for any biotechnologist. They form the backbone of producing pure, functional biological products for research, medicine, and industry. This TD emphasizes the theoretical principles and practical logic behind selecting and combining these methods efficiently.
- Enseignant: IDIR MOUALEK