In DNA fingerpriting, detection of hydridised DNA

Options

A. Electrophoresis
B. Blotting
C. Autoradiography
D. Centrifugation

Answer

**Step-by-Step Solution:**

1. **Understanding DNA Fingerprinting**: DNA fingerprinting is a technique used to identify individuals by their unique DNA profiles. It is often used in forensic science to link biological evidence from a crime scene to a suspect.

2. **Extraction of DNA**: The first step in DNA fingerprinting is to extract DNA from the biological sample (e.g., blood, hair, etc.) collected from the crime scene and the suspect.

3. **Cutting the DNA**: The extracted DNA is then cut into smaller fragments using restriction enzymes. These enzymes recognize specific sequences in the DNA and cleave it at those sites.

4. **Separation of DNA Fragments**: The next step involves separating the DNA fragments based on their size. This is typically done using gel electrophoresis, where an electric current is applied to a gel matrix, causing the DNA fragments to migrate through the gel.

5. **Transferring the DNA**: After separation, the DNA fragments are transferred to a membrane in a process known as blotting. This allows for the subsequent detection of specific DNA sequences.

6. **Adding Radioactive Probes**: Radioactive probes, such as P-32, are then added to the membrane. These probes bind to specific DNA sequences, allowing for the detection of hybridized DNA.

7. **Autoradiography**: The final step involves exposing the membrane to X-ray film or other detection methods to visualize the hybridized DNA. This process is called autoradiography, which allows scientists to see the locations of the radioactive probes that have bound to the DNA.

8. **Conclusion**: The method used to detect hybridized DNA in DNA fingerprinting is autoradiography, which utilizes the radioactive probes added in the previous step.

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