Question : Two blood sampleH A and B picked up from the crime scene were handed over to the forensic depertment for gentic finger printing . Describehow tle technique of genetic finger printing is carried out. How will it be confirmed whether the samplebelonged to the same individual or two differnent individunls?

Question : Two blood sampleH A and B picked up from the crime scene we

1.	Question : Two blood sampleH A and B picked up from the crime scene were handed over to the forensic depertment for gentic finger printing . Describehow tle technique of genetic finger printing is carried out. How will it be confirmed whether the samplebelonged to the same individual or two differnent individunls?
Answer» Solution :DNA Fingerprinting : This technique was DISCOVERED by Ales Jeffreys in 1985. The technique mvolved following steps Isolation and EXTRACTION of DNA from the ceJJ by centrifugation . By the help of enzyme RESTRICTION endonuclease, DNA molecules are digested. The FRAGMENT also contains VNTRs. The small DNA fragments are separated through gel electrophoresis set-up tha contains agarose polymer gel. The separated DNA fragments are transfered from electrophoresis plate to synthetic membranes like nitrocellulose or nylon membrane sheet called Southern blotting. The DNA probes are added which target a specific n~c~eot~de sequence which is complementary to them and this process is called hybridisation. The nylon membrane is EXPOSED to an X-ray film and dark orange coloured bands developed at sites where probes have bound to the DNA fragments. This is known as autoradiography. On comparing the DNA print of blood samples A and B, it can be confirmed that the blood sample picked up from the crime scene belongs to the same individual or to different individuals.