DNA Fingerprinting

            DNA Fingerprinting is also referred to as DNA profiling and DNA typing. It was first developed as an identification technique in England in 1985. The original use was to expose the presence of any genetic diseases. About three years later it became used to identify criminals through the analysis of genetic material and to settle paternity disputes. It is still used for those reasons today. The DNA fingerprinting process is called gel electrophoresis. It is a process that can sort pieces of DNA according to its size. The process is done by taking samples of DNA from the crime scene and comparing it with samples from the accused. Samples are taken from biological materials like blood, semen, hair, and saliva. In the testing process the DNA samples are first entered into the wells in a gel like substance called Agarose. The gel is placed between two electrodes, one negatively charged and the other positively charged. The wells in the Agarose are inserted on the negative side beca!.
             use DNA has a negative charge. Molecules of DNA then travel in lanes toward the positive side. Small molecules will travel farther than the bigger ones, because they have an easier time moving through the gel. So the molecules will then be assorted according to their size. Next, the gel is X-rayed to see the parallel bands (showed by black bars on the film) in each lane. The separated molecules of DNA form a pattern of parallel bands that show the structure of the DNA. The pattern should never change for one person. In a court of law, the results of a DNA fingerprinting examination can be used to convict or acquit an accused person. If the accused's DNA matches the one at the crime scene then that person could be convicted. Critics believe that a DNA fingerprint may not yet be reliable enough to use in the court system. They question how accurate a DNA fingerprint is and the cost of it. They believe that it is not very accurate because only a segment of DNA is used and not the complete strand.