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GATE 2025 BT – Question 27

Fundamentals of Biological Engineering · Downstream Processing: Filtration, centrifugation, cell disruption, chromatography, extraction, adsorption and drying · 1 mark · Multiple select

A recombinant protein is secreted extracellularly in soluble form by an E. coli culture. Which of the following downstream processes is/are involved in the purification of the extracellular secreted protein?

  1. Cell disruption
  2. Membrane ultrafiltration
  3. Solubilisation of inclusion bodies
  4. Liquid chromatography

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Show answer and explanation

Correct answer: (B) Membrane ultrafiltration; (D) Liquid chromatography

Explanation

The protein is already outside the cells and soluble, so the cells are removed and the supernatant is concentrated by ultrafiltration and purified by chromatography. Cell disruption and inclusion body solubilisation are for intracellular products.