DNA finger printing technique is based on

Options

A. restriction endonuclease
B. polymorphism in repetitive DNA
C. Gel electrophoresis
D. Southern blotting technique

Answer

**Step-by-Step Solution:**

1. **Understanding DNA Fingerprinting**: DNA fingerprinting is a technique used to identify individuals based on their unique DNA profiles. It helps in determining genetic relationships and is widely used in forensic science, paternity testing, and genetic studies.

2. **Basis of DNA Fingerprinting**: The DNA fingerprinting technique is primarily based on the Southern blotting technique. This method allows for the detection of specific DNA sequences within a complex mixture.

3. **Process of Southern Blotting**:
- **Isolation of DNA**: The first step involves extracting DNA from the cells of the individual whose fingerprint is being analyzed.
- **Digestion of DNA**: The isolated DNA is then digested using restriction endonucleases. These enzymes cut the DNA at specific sequences, resulting in fragments of varying lengths.
- **Separation of DNA Fragments**: The resulting DNA fragments are separated by gel electrophoresis. This technique uses an electric field to move the negatively charged DNA fragments through a gel matrix, allowing for the separation based on size.
- **Transfer to Membrane**: After electrophoresis, the separated DNA fragments are transferred onto a membrane, a process known as blotting.
- **Hybridization**: The DNA on the membrane is then hybridized with labeled probes that are complementary to the target DNA sequences. This step allows for the identification of specific fragments.
- **Detection**: Finally, the hybridized DNA is detected using autoradiography or other imaging techniques, revealing the unique pattern of bands that constitutes the DNA fingerprint.

4. **Conclusion**: The DNA fingerprinting technique is fundamentally based on the Southern blotting technique, which encompasses the processes of DNA isolation, digestion, electrophoresis, hybridization, and detection.

**Final Answer**: The DNA fingerprinting technique is based on the Southern blotting technique.

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