Arrange the various steps of DNA fingerprinting technique in the correct order.
(i) Separation of DNA fragments by electrophoresis.
(ii) Digestion of DNA by restriction endonucleases.
(iii) Hybridisation using labelled VNTR prode.
(iv) Isolation of DNA .
Detection of hybridised DNA fragments by auto-radiography.
(vi) Transferring the separated DNA fragments to nitrocellulose membrane.

Options

A. `(iv)to(ii)to(i)to(vi)to(iii)to(v)`
B. `(iv)to(i)to(ii)to(iii)to(vi)to(v)`
C. `(ii)to(i)to(iv)to(vi)to(iii)to(v)`
D. `(iii)to(v)to(iv)to(ii)to(i)to(vi)`

Answer

To arrange the various steps of the DNA fingerprinting technique in the correct order, we will follow the logical sequence of the process involved. Here’s the step-by-step solution:

1. **Isolation of DNA (Step iv)**: The first step in DNA fingerprinting is to isolate the DNA from the cells. This involves breaking open the cells and extracting the DNA from the nucleus.

2. **Digestion of DNA by restriction endonucleases (Step ii)**: Once the DNA is isolated, the next step is to digest the DNA using restriction endonucleases. These enzymes cut the DNA at specific sequences, resulting in smaller fragments.

3. **Separation of DNA fragments by electrophoresis (Step i)**: After digestion, the DNA fragments need to be separated based on their size. This is done through electrophoresis, where the DNA fragments are placed in a gel and an electric current is applied, causing the fragments to move and separate.

4. **Transferring the separated DNA fragments to a nitrocellulose membrane (Step vi)**: Once the DNA fragments are separated, they are transferred to a nitrocellulose membrane. This step helps in immobilizing the DNA fragments for further analysis.

5. **Hybridization using labelled VNTR probe (Step iii)**: After transferring the DNA to the membrane, the next step is hybridization. A labeled VNTR (Variable Number Tandem Repeat) probe is used to bind to specific DNA sequences on the membrane.

6. **Detection of hybridized DNA fragments by autoradiography (Step v)**: Finally, the hybridized DNA fragments are detected using autoradiography. This technique allows visualization of the DNA fragments that have bound to the VNTR probe, providing a DNA fingerprint.

### Final Order of Steps:
1. Isolation of DNA (iv)
2. Digestion of DNA by restriction endonucleases (ii)
3. Separation of DNA fragments by electrophoresis (i)
4. Transferring the separated DNA fragments to nitrocellulose membrane (vi)
5. Hybridization using labelled VNTR probe (iii)
6. Detection of hybridized DNA fragments by autoradiography (v)