The correct sequence of steps to obtain gene of interest from pool of DNA is:

A. Cutting of DNA using restriction endonuclease.

B. Viewing the ethidium bromide stained gel under UV light.

C. Loading of DNA in wells.

D. Cutting and extraction of DNA piece from gel.

E. Separation of DNA fragments according to their molecular size.

Choose the correct answer from the options given below:

A, C, E, B, D

The correct answer is Option (1)- A, C, E, B, D

A. Cutting of DNA using restriction endonuclease.

C. Loading of DNA in wells.

E. Separation of DNA fragments according to their molecular size.

B. Viewing the ethidium bromide stained gel under UV light.

D. Cutting and extraction of DNA piece from gel.

The process of cutting DNA using restriction endonucleases results in the formation of DNA fragments. During gel electrophoresis, DNA fragments separate based on their size and charge. The gel, typically made of agarose, acts as a molecular sieve that slows down the movement of DNA fragments as they migrate through the gel under the influence of an electric field.

Agarose, a natural polymer extracted from seaweeds, is commonly used as the matrix. The DNA fragments separate based on their size due to the sieving effect provided by the agarose gel.When an electric field is applied, the negatively charged DNA fragments move towards the positively charged anode. Smaller DNA fragments can move through the gel more easily and thus migrate faster towards the anode compared to larger fragments. As a result, DNA fragments separate into distinct bands according to their size, with smaller fragments traveling farther from the origin (where the DNA was initially loaded onto the gel) and larger fragments staying closer to the origin.

The separated DNA fragments can be visualized only after staining the DNA with a compound called ethidium bromide, followed by exposure to UV radiation. Without staining, the pure DNA fragments cannot be seen in visible light. After staining, you can observe bright orange-colored bands of DNA in an ethidium bromide stained gel exposed to UV light.

Once the DNA fragments are separated, they can be cut out from the agarose gel and extracted from the gel piece. This step is known as elution.

By using this principle, researchers can analyze and purify DNA fragments of interest, allowing them to study specific genes or genetic sequences, identify mutations, or perform various other molecular biology techniques.