DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample taken from a crime scene is compared with a DNA sample from a suspect. If the two DNA profiles are a match, then the evidence came from that suspect. Conversely, if the two DNA profiles do not match, then the evidence cannot have come from the suspect. DNA fingerprinting is also used to establish paternity.
Detecting maternal cell contamination
One of the major drawbacks of prenatal diagnosis is maternal cell contamination. The amniotic fluid or CVS sample contains the maternal DNA or maternal tissue, sometimes. Contamination increases the chance of false-positive results, especially in the case of carrier identification.Using VNTRs and STRs markers with PCR-gel electrophoresis, maternal cell contamination can be identified during pregnancy genetic testing.
In criminal investigations, the DNA fingerprint of a suspect’s blood or other body material is compared to that of the evidence from the crime scene to see how closely they match. The technique can also be used to establish paternity. First developed in 1984 by Alec Jeffreys, a British professor of genetics at the Univ. of Leicester.
DNA fingerprinting is generally regarded as a reliable forensic tool when properly done, but some scientists have called for wider sampling of human DNA to insure that the segments analyzed are indeed highly variable for all ethnic and racial groups.
Identification of blood relatives
No two individuals are genetically identical. To establish or to know blood relation between two unrelated individuals, the present method is adopted. Besides these, the present method is often employed for checking graft rejection in case of organ transplantation. Known as HLA typing, different markers of HLA region genes are amplified and matched between donor and recipient. The exact match score indicates graft acceptance. This means an organ can be transplanted.