Question

Arrange the following steps of DNA fingerprinting in proper sequence:
(A) Hybridization using labeled VNTR probe
(B) Separation of DNA fragments by electrophoresis
(C) Digestion of DNA by restriction endonucleases
(D) Blotting of separated DNA fragments to nylon
(E) Isolation of DNA
Choose the correct answer from the options given below:

• A. (C), (A), (B), (D), (E)
• B. (E), (C), (B), (D), (A)
• C. (B), (C), (D), (E), (A)
• D. (C), (D), (B), (A), (E)

Answer 1

The Correct Option is B

DNA fingerprinting is a technique used to identify and compare DNA samples. The process involves several critical steps that must be performed in a specific sequence to ensure accuracy and reliability. Here is the correct sequence of steps involved in DNA fingerprinting: 

1. Isolation of DNA (E): The process begins with the extraction of DNA from cells. This is crucial as it provides the template necessary for further analysis.
2. Digestion of DNA by restriction endonucleases (C): This step involves cutting the DNA into smaller fragments using specific enzymes known as restriction endonucleases.
3. Separation of DNA fragments by electrophoresis (B): The DNA fragments are then separated according to size using a technique called gel electrophoresis, which applies an electric field to move the fragments through a gel matrix.
4. Blotting of separated DNA fragments to nylon (D): Once separated, the DNA fragments are transferred from the gel onto a nylon membrane. This process is known as blotting and allows for further analysis.
5. Hybridization using labeled VNTR probe (A): Finally, specific DNA sequences are identified using labeled probes that bind to the variable number of tandem repeats (VNTRs), unique to every individual. This step facilitates the comparison and identification of DNA footprints.

Therefore, the correct sequence of steps is: (E), (C), (B), (D), (A).

Answer 2

The steps involved in DNA fingerprinting are as follows:

• Isolation of DNA (E): The first step is to extract the DNA from the sample (blood, hair, tissue, etc.).
• Digestion of DNA by restriction endonucleases (C): The DNA is then cut into smaller fragments using restriction enzymes.
• Separation of DNA fragments by electrophoresis (B): The DNA fragments are separated based on their size using agarose gel electrophoresis.
• Blotting of separated DNA fragments to nylon (D): The separated DNA fragments are transferred from the gel onto a nylon membrane for further analysis.
• Hybridization using labeled VNTR probe (A): A labeled probe (which binds to specific DNA regions) is used to detect the presence of specific DNA sequences, revealing the individual's unique DNA pattern.

Thus, the correct sequence is (E), (C), (B), (D), (A).