Which of the following step is not the part of downstream processing?

The correct answer is Option (3) → No quality control testing of product

After the product is made in the bioreactor, it goes through downstream processing before it can be sold: separation and purification, formulation with preservatives, clinical trials for drugs, and strict quality control testing.

Option (1) Separation and purification — Part of downstream processing. After the product is formed in the bioreactor, it must first be separated from the culture and then purified. These are the two main steps of downstream processing.

Option (2) Product formulation with suitable preservatives — Part of downstream processing. The product is made ready for storage and use.

Option (3) No quality control testing of product — Not part of downstream processing. Strict quality control testing is needed; leaving it out is not a step. The word ‘No’ turns a real step into a wrong one.

Option (4) Clinical trials of drugs — Part of downstream processing. A drug must pass clinical trials before it is marketed.

NCERT Extract:
Downstream Processing –