Question

Some steps of DNA fingerprinting are given below. Identify the correct sequence from the options given.
1) Electrophoresis of DNA fragments
2) Hybridisation with DNA probe
3) Digestion of DNA by RENs
4) Autoradiography
5) Blotting of DNA fragments to nitrocellulose membrane

• A. 3 $\to$ 1 $\to$ 5 $\to$ 2 $\to$ 4
• B. 1 $\to$ 3 $\to$ 5 $\to$ 4 $\to$ 2
• C. 3 $\to$ 1 $\to$ 2 $\to$ 5 $\to$ 4
• D. 1 $\to$ 5 $\to$ 3 $\to$ 2 $\to$ 4

Answer 1

The correct option is A

3 $\to$ 1 $\to$ 5 $\to$ 2 $\to$ 4

DNA fingerprinting is also known as DNA profiling. This is the method that is used to identify the criminals and suspects. There are many steps involved in DNA fingerprinting.

The first step is isolating the desired DNA which can be performed chemically, mechanically, or enzymatically.

The second step is cutting the DNA into several pieces by restriction enzymes.

The third step is sorting the DNA pieces by gel electrophoresis. The DNA will be separated by size.

The next step is denaturing the DNA fragments. The next step is blotting the DNA The gel with the size-fractionated DNA is applied to a sheet of nitrocellulose paper or nylon membrane.

In order to analyze a Southern Blot, a radioactive genetic probe is used in a hybridization reaction with the DNA. The X-ray film helps to analyze the fragments.

Thus the correct answer is option A.