Criminal Investigation: DNA Testing

The role of DNA is perhaps the most vital in investigations today. DNA or Deoxyribonucleic acid is present in every cell of the body, except Red Blood Cells and stores in it the genetic data about the person, which is unique for every individual. The genes r inherited form the parents, half coming from the father and the other half from the mother.

The DNA is found inside the chromosomes that are inherited from the parents. Apart from identical multiple births, DNA will always differ from one person to the other and so is probably the most conclusive identifying object. But still at times DNA samples from two people can look very similar and advanced tests need to be performed to tell them apart. DNA is generally collected from bodily fluids found at the crime scene like blood, saliva, sperm, etc.

Producing a DNA print, or profile, comprises of primarily hauling out the DNA from the cells. The elongated DNA fibres shortened with the help of constraining enzymes, that kind of act like DNA scissors used to chop the DNA off at particular points. Because the DNA fibres will differ for a couple of different people, the DNA will be chopped off at different junctions, generating portions of dissimilar measurements lengthwise.

The DNA chips are consequently split up atop a gel with the help of a procedure known as electrophoresis. Once an electric wave is set on the gel, the DNA pieces shift from one side of the gel to another at diverse time spans, establishing a blueprint of bands. The speed and direction is dependent on largely on their electrical charge and their magnitude. Once done, the bands of DNA are shifted to a membrane. The bands need to be seen and so the radioactive probes are subjected to the membrane. As soon as an x-ray film is positioned on top of the membrane, the radioactive substance photocopies the DNA banding blueprint on the film, n this a DNA print is found.

Matching the DNA print to the DNAs found at the crime scene, the investigators try to get hold of the criminals.