Downstream Processing Mixing in bioreactors

Downstream Processing Mixing in bioreactors 

Bioengineering

1. Basic pathways for protein synthesis
a. What are the key steps involved?
b. The need for genetic manipulations and regulatory concerns.
c. Name one commonly used vector systems for mammalian host cells and provide a short description of the functioning.

2. Key elements when considering Bioreactor scale-up

a. Mention minimum of five scale-up considerations.
b. What is the Damkohler number and what role does it play in substrate injection?
c. Name three other dimensionless numbers important in bioprocess scale-up and what relationship do these have either with the Damkohler number or viscosity or density?

3. Downstream processing
a. What is downstream processing?
b. What entails a typical downstream process for monoclonal antibodies? In brief, Provide a stepwise purification method. (Picture or diagram with a brief explanation will suffice)
c. What is the working principle of affinity-based chromatography?

4. Mixing in bioreactors
a. How is mixing typically achieved in a bioreactor?
b. What is the difference between a Newtonian versus non-Newtonian liquids?
c. What is the difference between laminar flow versus turbulent flow?

5. Critically Review the following research article from Nature Publishing
“Datar, R., Cartwright, T. & Rosen, C. Process Economics of Animal Cell and Bacterial Fermentations: A Case Study Analysis of Tissue Plasminogen Activator. Nat Biotechnol 11, 349–357 (1993). https://doi.org/10.1038/nbt0393-349

a. What is Tissue Plasminogen Activator (tPA) and describe its mechanism of action?
b. Authors compare CHO versus Bacterial cells, describe the major differences seen between the two systems. (create a table of differences)
c. Provide a brief critical view of their work. Knowing that it is difficult to select the correct host versus vector system, is their approach sound and would recent developments in the CHO-based production provide any changes in their price evaluations?