Jennifer Tran
Mr. Tucker
AP Biology
26 August 2015
The Uses of DNA: DNA Fingerprinting
Sir Alec Jeffreys’ 1984 discovery of DNA fingerprinting in England has revolutionized the criminal justice system by enabling legal entities to determine innocence or guilt of a suspect to a much higher level of accuracy(Butler). This discovery has also provided the ability to identify victims of natural disasters or catastrophes like 911(Lippincott). Additionally, DNA testing or profiling, has helped doctors and researchers to identify medical conditions and illnesses, determine pre-existing conditions and prevent them sometimes before they actually occur(Roewer). Also, DNA could be separated from different individuals in mixed stains like, when two or
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It has greatly made an impact on crime cases, especially in forensic investigations because it not only helped find suspects, but it also improves the accuracy of who the suspect is and up until now, DNA fingerprinting is still continuing to grow and flourish itself for greater use in the future.
Four years have passed since the discovery of DNA fingerprinting. During those four years people have learned that the four probes known to allow DNA fingerprinting in the human (M13, Jeffreys’ core sequence, the human α globin hypervariable region [HVR]) were checked for their ability to reveal “genetic barcodes” in animals(Georges et al.). Jeffreys’ core sequence, and the Per probe uses the four different probes(Lippincott). Depending on the particular probe-species combination, the fingerprints are polymorphic enough to be used efficiently in animal identification, paternity testing, and as a source of genetic markers for linkage analysis(Butler). These markers should substantially accelerate the mapping of genes affecting economically important traits(Roewer). If this revealed “genetic barcodes” in animals then the same could also be done for humans and it could possibly help out with the Human Genome Project that was started in 1990(Friedland). James D. Watson constructed the Human Genome Project was for further biological study to discover all the estimated 20,000-25,000 human genes to make it accessible(Friedland).
Another
DNA testing is a critical and accurate tool in linking accused and even convicted criminals for crimes, and should be widely used to assess guilt or innocence before jail sentences are imposed. It was started up by scientists Francis C. Crick and James D, Watson in 1953 as they had described the uses, structures and purpose of the DNA “deoxyribonucleic acid” genetic fingerprint that contains organism information about an individual (testing
Due to the uniqueness of DNA it has become a powerful tool in criminal investigations
DNA forensics can also narrow down suspect pools, exonerate innocent suspects, and link crimes together if the same DNA is found at both scenes. However, without existing suspects, a DNA profile cannot direct an investigation because current knowledge of genotype-phenotype relation is too vague for DNA phenotyping. For example, a profile from a first time offender that has no match in any database may give the information that the criminal is a left handed male of medium stature with red hair and freckles. It would be impossible to interview every man who fits that description. However, with available suspects, DNA forensics has many advantages over other forms of evidence. One is the longevity of DNA. Although it will deteriorate if exposed to sunlight, it can remain intact for centuries under proper conditions (Sachs, 2004). Because DNA is so durable, investigators can reopen old cases to reexamine evidence.
DNA profiling involves testing mini-satellites one at a time which then goes on to produce an image which is much simpler than genetic fingerprinting. It provides a pattern which is unique to a particular person and is therefore suitable for forensic purposes. (Turnpenny, P et al 2005).
In current events, DNA fingerprinting is a vital instrument soldiers who are unidentifiable after war. Marieb wrote (435), “The U.S military takes blood and saliva samples from every recruit so it can identify soldiers killed in the line of duty.” In contrast, in the past, there were rudimentary ways to recognize
While DNA profiling is still considered to be fairly new , the analysis of the human genetic variation began more than a century ago with the discovery of the human ABO blood group. Karl Landsteiner realized that these variations in humans could be used to solve crimes. ABO could be used to exclude suspects, but police needed something that could definitively point the finger at a suspect. In 1984, Alec Jeffreys discovered hypervariable loci, also known as minisatellites. He discovered that the
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.
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
Sir Alec Jeffreys is one of the greatest contributors to modern genetics. In September 1984, Jeffreys was doing a studying on hereditary diseases in families. His main focus was to resolve paternity and immigration issues by demonstrating the genetic links between individuals. Jeffreys used Restriction Fragment Length Polymorphism (RFLP) to analyze Deoxyribonucleic Acid (DNA). Dr. Jeffreys discovered that repetitive patterns of DNA, known as Variable Number of Tandem Repeats (VNTRs), were present in all human beings but that they were different, everyone has different patterns.
DNA profiling was at first made as a framework for choosing paternity, in which tests taken under clinical conditions were examined for innate affirmation that could association watchman to adolescent. It initially progressed into the courts in 1986, when police in England asked sub-nuclear analyst Alec Jeffrey’s, who had begun looking at the use of DNA for wrongdoing scene examination, to use DNA to check the confirmation of a 17 year-old child in two ambush murders in the English Midlands. The tests showed the youngster was frankly not the offender and the genuine attacker was over the long haul found, furthermore using DNA testing.
DNA profiling technologies have had a considerable impact on how forensic science and criminal investigation have been understood, carried out, and regulated in the last 25 years. Current methods of forensic DNA profiling (known also as DNA fingerprinting and DNA typing), based on Polymerase Chain Reaction (PCR) amplifications of a varying number of Short Tandem Repeat (STR) loci found at different locations on the human genome, are regularly described as constituting the “gold standard for identification” in contemporary society. Prior to the implementation of PCR based extraction and amplification methods in the 1990’s, the initial uses of DNA fingerprinting (based on Multiple and Single Locus Probes) were largely confined to reactive
DNA fingerprinting was discovered by Professor Sir Alec Jeffreys from the University of Leicster. After spending time studying molecular biology in Amsterdam with Dick Flavell, Jeffreys moved to the university and set out to “marry the new
Law Enforcement keep notes on arrests that have founded people innocent of crimes, and retention of an innocent person's DNA can be charge or otherwise, seen as a invasion of that person’s privacy and civil liberties. Dr. Alec Jeffrey, a former professor at the University of Leicester laboratory, consulted with his lawyers to develop the new type of technique called DNA profiling. His technique would prove that DNA fingerprinting (profiling) can individualize evidence compared to the blood typing. DNA profiling compares 13 standard STRs to form a profile. The analysis used by the scientists, uses PCR and STRs to profile an individual. It is highly unlike that two individuals’ identical numbers of repeats for all 13 STRs, will match, which DNA fails is hardly never due to a successful match of 385 million to 1. This makes DNA profiling the most accurate tool in Forensics.
DNA fingerprinting is a forensic technique used to identify individuals by features of their DNA. A DNA profile is a small set of DNA variations that is very likely to be different in all unrelated individuals, thereby being as unique to individuals as are fingerprints. First developed and used in 1984, DNA fingerprinting is used in, commonly, for parentage testing and criminal investigation. Its purpose is to identify a person or to place a person at a crime scene, methods that are employed globally in forensic science presently. Another aspect, which the technique for DNA fingerprinting helps, is being used in the establishment of animal and floral populations and has dramatically transformed the fields of zoology, botany, and agriculture.
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