Question

What are the negatives of having a very long protein purification scheme with many steps?

Answer 1

Protein purification involves isolating proteins from the source, based on differences in their physical properties. The objective of a protein purification scheme is to retain the largest amount of the functional protein with fewest contaminants. So, the purification scheme of a protein must be optimized to complete this process in the least number of steps.
The negatives of large scale protein purification process:
In large scale protein purification, a downstream production process must achieve the required purity and recovery with complete safety and reliability, and within a given economic framework, whereas Economy is a very complex issue in large scale protein purification.
In commercial production the time to market can override issues such as optimisation for recovery, capacity or speed.
There is a chance of batch failure in large scale protein purification, so robustness and reliability are also of great concern since a batch failure can have major consequences.
Since, large scale protein purification requires longer periods of time, there are chances of several types of hazards to take place. So, special safety issues may be involved in purification of biopharmaceuticals, such as detection or removal of infectious agents, pyrogens, immunogenic contaminants and tumorigenic hazards.
Since, it is very long period process, many contaminants may occur in the process. So, it may be necessary to use analytical techniques targetted towards specific contaminants in order to demonstrate that they have been removed to acceptable levels.
In large scale protein purification process, simple bed adsorption method cannot be used, it requires streamline expanded bed adsorption.
In large scale protein purification, too many steps have to be carefully monitored as failure of any single step may result in spoilage of the entire purification process. So, It is important to consider all aspects: sample extraction and clarification, sample loading capacity, flow rate during equilibration, binding, washing, elution and cleaning, and the need for cleaning-in-place procedures.
When scaling up a purification it is important to verify that the high resolution achieved from the laboratory scale polishing step is maintained when applying preparative sample volumes to large scale columns.
Most precipitation techniques are not suitable for large scale preparations. Only very few types precipitation techniques can be used.