Question

Choose the correct option to indicate the techniques used for product purification during downstream processing of the recombinant gene product.
I. Chromatography
II. Heat shock
III. Centrifugation

• A. I and II
• B. II and III
• C. I and III
• D. Only I

Answer 1

The correct option is D Only I

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

Once the concentration or density of the product expressed by the host cells in the culture reaches the optimal quantity, it is separated and purified. Separation and purification of the product are components of downstream processing.

Separation of the product from the medium involves centrifugation. Centrifugation is used to separate the cellular debris from the culture media due to the differences in their densities under high centrifugal force.

The technique that is generally used for purification of the desired gene product is chromatography. Chromatography is a technique based on a principle in which molecules in a mixture can be separated on the basis of their solubility.

By exposing cells to a high temperature, or heat shock, a pressure difference between the outside and the inside of the cell is created, that induces the formation of pores, through which foreign DNA can enter.

Hence the technique used for product purification during downstream processing is chromatography.