Application of DNA finger printing • Forensic analysis - It can be used in the identification of a person involved in criminal activities, for settling paternity or maternity disputes, and in determining relationships for immigration purposes. • Pedigree analysis – inheritance pattern of genes through generations and for detecting inherited diseases. • Conservation of wild life – protection of endangered species. By maintaining DNA records for identification of tissues of the dead endangered organisms.
• Anthropological studies –It is useful in determining the origin and migration of human populations and genetic diversities. . Using probes to identify specific DNA A radioactive probe (DNA labeled with a radioactive substance) is added to the DNA bands. The probe attaches by base pairing to those restriction fragments that are complementary to its sequence.
The probes can also be prepared by using either ‘fluorescent substance’ or ‘radioactive isotopes’. . Hybridization with probe After the probe hybridizes and the excess probe washed off, a photographic film is placed on the membrane containing ‘DNA hybrids’. .
Exposure on film to make a genetic/DNA Fingerprint The radioactive label exposes the film to form an image (image of bands) corresponding to specific DNA bands. The thick and thin The radioactive DNA probe is prepared Excess DNA probe is washed off The DNA on gels is denatured by using alkaline chemicals or by heating. The DNA probe binds to specific DNA sequences on the membrane The DNA fragments are separated into bands during electrophoresis in an agarose gel The DNA band pattern in the gel is transferred to a nylon membrane by a technique known as southern blotting At this stage, the radioactivity probe is bound to the DNA pattern on the membrane X-ray film is placed next to the membrane to detect the radioactive pattern The X-ray film is developed to make visible the pattern of bands which is known as a DNA fingerprint Blood sample DNA is extracted from blood cells DNA is cut into fragments by a restriction enzyme Many copies of the DNA produced by PCR Fig. .
The Steps involved in DNA Fingerprinting technique XII Std Zoology Chapter XII Std Zoology Chapter Molecular Genetics promoter and regulator. It is an example of negative control of transcription initiation. Human genome project, a mega project was aimed to sequence every gene in the human genome. Polymerase chain reaction is an in vitro method of synthesis of nucleic acids wherein, a specific DNA segment is amplified rapidly without concomitant replication of the rest of the DNA molecule.
DNA fingerprinting is a technique to identify variations in individuals of a population at the DNA level. It has immense applications in the field of forensic analysis, pedigree analysis, anthropological studies, and conservation of wild life.