DNA Polymorphisms and Fingerprinting: Key to Identification

Why in the News?

DNA fingerprinting, based on polymorphisms and STR analysis, is crucial for forensic investigations, ancestry tracing, and disaster victim identification. Recent advancements have enabled DNA extraction from 65,000-year-old remains, offering insights into ancient human genetics and forensic science.

DNA Polymorphisms and Fingerprinting: Key to Identification

How DNA Fingerprinting Works

  • DNA fingerprinting is a technique that identifies individuals using their unique STR patterns.
  • DNA is extracted from teeth, bones, blood, saliva, and skin cells for analysis.
  • The Polymerase Chain Reaction (PCR) is used to amplify small DNA samples by producing millions of copies in a short time.
  • Capillary electrophoresis helps separate DNA fragments based on their size and charge, generating a unique DNA profile.
  • Identical twins are the only individuals who share the same DNA fingerprint.

Applications of DNA Fingerprinting

  • Used in forensic investigations to identify suspects from crime scene evidence like blood stains, saliva, and sweat.
  • Helps in parent-child relationship verification and disaster victim identification from mortal remains.
  • Plays a crucial role in organ transplantation by confirming donor-recipient matches.
  • DNA has been successfully extracted from 65,000-year-old human remains, enabling insights into ancient human ancestry.
  • DNA fingerprinting has also been used to exonerate wrongly accused convicts.

What Are DNA Polymorphisms?

  • DNA polymorphisms are genetic variations in specific DNA sequences that differentiate individuals.
  • They exist in chromosomes and help in tracing ancestry by identifying whether a chromosome came from the father’s or mother’s lineage.
  • Short Tandem Repeats (STRs) are common polymorphisms where specific DNA sequences repeat multiple times.
  • These variations form the basis of DNA fingerprinting, a method used to identify individuals.