DNA Restriction Fragmentation Patterns

DNA samples can be extracted from hair, blood and skin. Siblings have different DNA fingerprints because everyone has 23 pairs of chromosomes and for each pair one is one of your mother’s chromosomes and the other is your father’s chromosomes. Other than identical twins no other people have exactly the same DNA. DNA fingerprinting is used every day to determine whose parents or siblings are whose, it is used in crime scenes to determine who was at the scene, can be used to determine where a certain inherited gene is inherited from and it can be used to identify a body that is deceased. During electrophoresis an electric current passes through the agarose gel, therefore moving the DNA samples through the gel. The smaller the DNA fragment the faster it moves through the gel. The finished product will look like a series of bands, some will match up and some won’t. The different bands in electrophoresis represent different gene fragments.

Indeed DNA profiling has rapidly transform the field of forensics. DNA profiling is the scientific analysis of evidence for crime scene investigation and other legal proceedings. DNA profiling is mostly used by forensic scientists and crime lab technicians. To identify criminals and victims using trace evidence like hair or skin samples. To produce a DNA profile, scientists compare sequences in the genome that vary from person to person. The typical steps in DNA profiling are DNA samples are isolated from the crime scene, suspect, victims, or other evidence. The next selected sequences from each DNA sample are amplified (copied many times) to produce a large sample of DNA fragments. Finally the amplified DNA regions are compared using a gel. All together, these steps provide data about which samples are from the same individual and which sample is unique.

Basically, our DNA (deoxyribonucleic acid) is our genes, and every person, except for twins, are born with a different DNA profile and that is in a giant database, containing every DNA profile of every person in the world. DNA testing started in 1985 by scientist Alec Jeffreys and was first used to solve a crime a year later. Before 1985 DNA evidence could not be used in court because it wasn’t invented yet, this increased the number of wrongful convictions which would have been prevented using DNA analysis. However, DNA analysis can still be used to solve crimes that occurred prior to the invention of DNA analysis, with a sufficient amount of DNA to be analyzed of course, which is a very small amount. Only a small amount of DNA is needed to find out who it belongs to, it can be found in blood, saliva, finger residue, hair, skin, semen and more.

(c) DNA fingerprinting could be used to exonerate or to convict suspected criminals. DNA fingerprinting could also be used to build phylogenetic trees

So you ask, "How does this work to catch or release criminals?" DNA is very simple and small. Everyone has different patterns. Using certain machinery to detect a person's DNA solves these patterns. This evidence will create a future in crime scene investigation.

After the spike in DNA discoveries and confirmations that could be compared to the 1849 California gold rush, scientists began to try to find other uses for DNA. Since then, DNA has been used for many things such as finding criminals and confirming paternity/maternity. Also DNA has been used to track diseases and problems that start at the molecular level. Three of the newer advances in DNA technology are DNA Fingerprinting, Recombinant DNA (rDNA) and Paternity/Maternity Tests.

DNA fingerprinting was introduced around 1986 to identify an alleged suspect in a rape-murder case (Panneerchelvam and Norazmi 22). Since then, using forensic DNA analysis has become more prevalent and has helped to exonerate many innocent suspects involved in such cases. Despite being used in only one percent of criminal cases, DNA tests have helped to acquit over 25 percent of wrongfully accused suspects ("Can DNA Demand a Verdict?"/Baird, Neufeld, and Scheck, 34). As of 2008, over 120 countries use some sort of forensic DNA analysis in cases like these ("INTERPOL Global DNA Profiling").

DNA analysis is a forensic tool that allows a suspect to be linked to a crime scene. Using the DNA analysis method, requires law enforcement officers to obtain DNA from the suspect and compare the suspects DNA,

Due to the uniqueness of DNA it has become a powerful tool in criminal investigations

DNA was only gaining momentum in 1980, when Sir Alec Jeffreys discovered something that would change our world, DNA Profiling. DNA profiling is the use or extraction of human cells to be profiled. Whether they are fresh or dried-out, the cells can be tested. (Suzanne Elvidge, “Forensic Cases: Colin Pitchfork, First Exoneration Through DNA”) Sir Jeffreys first started the process of discovering genomics ability to advance our society by applying this to different types of DNA. By doing so, Jeffreys discovered that there are billions of variations in DNA sequences. In fact, the human body has 10 million different sites at which one person’s DNA sequence can vary from another’s. (University of Leicester, “The Science Behind Genetic Fingerprinting”) Jeffreys’ discovery then allowed for DNA profiling to be used in the United Kingdom, where Sir Jeffreys conducted his research. With the research and testing performed in Europe, DNA profiling was now applicable in the United States. Detectives such as Joe Horgas took advantage of this

Human DNA is very similar to one another, but only about 0.1% is different from the next person. That 0.1% can tell a person’s eye color, hair color, and other physical features. DNA analyst are able to take a drop of blood, the size of a dime, and duplicate the number DNA found in that drop. With the ability to duplicate DNA, analysts can have a back-up, in the event a human error were to occur. Analyst can tell you exactly where your ancestors came from and the percentage that is still inside your DNA. DNA is a very powerful tool that can identify a murder if the individual left any blood, saliva, skin tissue, hair or semen. The education needed to be able make use of the DNA consists of a great deal of science classes.

Deoxyribonucleic acid (DNA) has been used to analyze and prove innocence or guilt of suspects of crimes with great accuracy. DNA is part of everyday life. It is the heredity material in humans and almost all other organisms. While being part of an investigation. DNA has helped to solve crimes. There is a couple ways that DNA left behind can be tested to solve a crime. Either if the suspect has been caught and or had his or her DNA tested, or if he or she has left behind any biological evidence. Which then needs to be tested to see if it matches the DNA found in the crime scene to his or hers DNA. The result to this comparison may help establish if the suspect committed the crime.

DNA fingerprinting is a technique that is used to determine how likely it is whether genetic material came from a specific person or family group. Since 99% of human DNA is identical, that means that it is only 1% of our DNA which is different, and it is that 1% that we look at when we are attempting to determine the origin of a DNA sample.

The process of DNA fingerprinting in humans involves the replication and arrangement of extracted DNA, to create a pattern/fingerprint that is viable for comparison. This process involves the application of DNA extraction, digestion by restriction enzymes, Polymerase Chain Reaction (PCR) and gel electrophoresis. This results in a DNA profile with bands of varying widths that can be used for the comparison of genetic information. DNA extraction occurs in three stages. Firstly, a

The use of gel electrophoresis to separate DNA fragments by size and charge can be used in genetic testing, like paternity or maternity tests. This method could allow the DNA of the child to be accurately compared with the DNA fragments and banding patterns of one of the parents. This can allow one to determine the biological parents of a child. Another important use of DNA fingerprinting is the diagnosis of many inherited diseases. The DNA fingerprint of a person can allow doctors to determine if they carry an inherited disease through comparison of the band patterns, and if they are diagnosed, a treatment for the disease can be provided early on. DNA fingerprinting is extremely useful and essential in the improvement of lives through the medical field, as well as its other uses in solving crimes and cases of biological