Question

Assertion :Hybridoma cells are shifted to a medium deficient nutrient which cannot be synthesised by myeloma cells. Reason: This medium allows selection of hybridoma cells.

• A. Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion
  
• B. The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion
  
• C. Assertion is true but the Reason is false
  
• D. Assertion is false but the Reason is true

Answer 1

The correct option is A Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion

Antibodies derived from a single clone of cells which recognize only one kind of antigen, are called monoclonal antibodies. The major steps in the production of monoclonal antibodies with hybrid cultures are mentioned below: (i) a mouse rat or some other animal is injected with specific antigen (against which the antibodies are required); (ii) the animal starts developing antibodies against the antigen in B-lymphocyte cells in spleen; (iii) the spleen of animal is removed and its B-lymphocyte cells are isolated; (iv) similarly, the cells producing bone marrow cancer (myeloma cells) are isolated. These cells should not be able to synthesise their own nutrients; (v) the two types of cells (ie myeloma cells and antibody-producing cells) are made to fuse in cultures. The fused cells are called hybridomas. (vi) the entire culture is shifted to a medium deficient in the nutrient needed by the myeloma cells where myeloma cells cannot survive. In this medium all the unfused myeloma cells die and only hybridoma cells survive; (vii) the surviving hybridoma cells are allowed to multiply separately and each clone is tested for its ability to produce a desired antibody; (viii) the clones which show positive results are isolated and cultured for large scale production of the antibody.