Question

Give an account on DNA fingerprinting.

Hint:

DNA fingerprinting = "genetic barcode" unique to every person, useful in forensics, paternity testing, and genetic studies.

Answer 1

DNA fingerprinting is a technique used to identify individuals based on their unique DNA sequence patterns. It was developed by Alec Jeffreys in 1984. In India, it was pioneered by Dr. Lalji Singh, known as the "Father of DNA Fingerprinting in India." Principle: It is based on the polymorphism in repetitive DNA sequences, particularly VNTRs (Variable Number of Tandem Repeats) that vary from individual to individual. Steps of DNA Fingerprinting: \begin{enumerate} \item DNA Isolation: Extraction of DNA from cells such as blood, hair root, or saliva. \item Restriction Digestion: DNA is cut into fragments using restriction endonucleases. \item Separation: Fragments are separated by gel electrophoresis. \item Hybridization: Fragments are transferred to a nylon membrane and hybridized with radioactive DNA probes specific to VNTRs. \item Autoradiography: The pattern of bands obtained on X-ray film represents the DNA fingerprint. \end{enumerate} Applications: \[\begin{array}{rl} \bullet & \text{Criminal investigations and forensic science.} \\ \bullet & \text{Paternity and maternity testing.} \\ \bullet & \text{Identification of genetic disorders.} \\ \bullet & \text{Study of genetic diversity and evolutionary biology.} \\ \end{array}\]