Question

All of the following statements about hybridoma technology are true except

• A. Specific antibody-producing cells are integrated with myeloma cells
• B. Myeloma cells with mutation in salvage pathway grow well in HAT medium
• C. Aminopterin, a folate antagonist, inhibits de-novo pathway
• D. HGPRTase and thymidylate synthetase are required for the salvage pathway

Hint:

Hybridoma technology is a powerful tool for monoclonal antibody production, and the use of HAT medium helps select hybrid cells with both antibody-producing capabilities and the ability to survive under selective conditions.

Answer 1

The Correct Option is B

Hybridoma technology involves the fusion of specific antibody-producing cells (usually B cells) with myeloma cells (cancerous plasma cells) to produce hybrid cells called hybridomas. These hybridomas can continuously produce antibodies. The key steps and components involved include:

(1) Specific antibody-producing cells are integrated with myeloma cells (Option 1):
- This statement is true. In hybridoma technology, antibody-producing B cells are fused with myeloma cells to create hybridomas capable of producing specific antibodies.

(2) Myeloma cells with mutation in salvage pathway grow well in HAT medium (Option 2) - Incorrect:
- This statement is false. Myeloma cells are defective in the salvage pathway, meaning they cannot synthesize nucleotides through the salvage pathway alone. In HAT medium, which contains aminopterin (a folate antagonist), only the hybrid cells that can use the salvage pathway (from the fused B cells) will survive. Myeloma cells with a mutation in the salvage pathway cannot grow in HAT medium because they cannot survive without the functional salvage pathway.

(3) Aminopterin, a folate antagonist, inhibits the de-novo pathway (Option 3):
- This statement is true. Aminopterin inhibits the de-novo synthesis of purines and pyrimidines by blocking the action of dihydrofolate reductase, forcing cells to rely on the salvage pathway for nucleotide synthesis.

(4) HGPRTase and thymidylate synthetase are required for the salvage pathway (Option 4):
- This statement is true. The hypoxanthine-guanine phosphoribosyltransferase (HGPRT) enzyme is essential for the salvage pathway of purine metabolism, and thymidylate synthetase is involved in the salvage pathway for pyrimidine synthesis.

Conclusion: The incorrect statement is Option 2. Myeloma cells with mutations in the salvage pathway cannot grow well in HAT medium, as they lack the necessary enzymes to utilize the salvage pathway for nucleotide synthesis.