Question

What are transformants and non-transformants?

Answer 1

Transformation :

1. The process of taking up foreign DNA by the bacterial cells is called Transformation.
2. The bacterial cells that take up the foreign DNA are called transformants, while the bacterial cells that do not take foreign DNA are called non-transformants.
3. The transformants are distinguished from non-transformants with the help of antibiotic-resistant genes in the cloning vector.

Transformants:

1. The cells that take up foreign DNA by transformation are known as transformants.
2. Transformants undergo transformation.

Non-transformants:

1. The cells that do not take up foreign DNA by transformation are known as non-transformants.
2. Non-transformants do not undergo transformation.

Example :

1. A cloning vector such as plasmid contains an antibiotic resistance gene for ampicillin and tetracycline antibiotics and contains the site for insertion of foreign DNA.
2. When the foreign DNA is inserted into the plasmid, it is called recombinant DNA.
3. This R-DNA is transferred to the host genome (bacteria) by the heat shock method i.e to make the host cell wall (bacteria) susceptible to taking up the foreign DNA.
4. This process called transformation occurs when the bacteria are grown in cultures containing antibiotics ampicillin and tetracycline, the appearance of blue and white colonies indicates transformants and non-transformants.
5. The blue bacterial colony indicates transformants and the white bacterial colony indicates non-transformants.