Question

Which of the following is not a component of downstream processing?

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

Answer 1

The correct option is A Expression

Obtaining the foreign gene product from a living source such as a genetically engineered organism, is known as bioprocessing.

It consists of two stages-upstream processing and downstream processing.

Expression of the foreign gene within a genetically engineered organism occurs at a large scale in the culture medium inside a bioreactor. This is the biosynthetic phase and is a component of the upstream processing.

Once the concentration or density of the product expressed by the host cells in the culture reaches the optimal quantity, it needs to be extracted out for use.

Separation of the expressed gene product from the culture media and its purification are the components of downstream processing.

Downstream processing is followed by formulation of the desired product with preservatives to increase its shelf life. This is further followed by strict clinical trials and quality control measures.

Therefore, the expression of the foreign gene is not a component of downstream processing.

Option a is the correct answer.