Uses of DNA Technology

Uses of deoxyribonucleic acid TechnologyIntroductiondesoxyribonucleic acid typing was first utilisationd in Great Britain for law enforcement purposes in the mid- 1980s and has revolutionized rhetorical science and the powerfulness of law enforcement to match perpetrators with crime scenes. It wasnt employed in the United States until 1987. deoxyribonucleic acid profiling has changed forensic science. deoxyribonucleic acid technology has given police and the courts a means of identifying the rummys of rapes and murders. Thousands of cases get been closed and innocent suspects freed with guilty iodins punished because of the power of a silent biological witness at the crime scene. Today, the federal official authorisation of investigating accomplishs the bulk of the forensic desoxyribonucleic acid typing for local anaesthetic and state law enforcement agencies. In savage investigations, deoxyribonucleic acid from seeks of hair, bodily fluids or scratch at a crime sce ne is comp ared with those obtained from suspected suspects. (http//faculty.ncwc.edu) desoxyribonucleic acid fingerprinting, or deoxyribonucleic acid typing (profiling) as it is now known, was first describe in 1985 by an position factorticist named Alec Jeffreys. Dr Jeffreys found that certain regions of desoxyribonucleic acid contained desoxyribonucleic acid sequences that were repeated everyplace and over again next to each another(prenominal). He withal discovered that the number of repeated sections present in a sample could differ from somebody to individual. By developing a proficiency to examine the length variation of these deoxyribonucleic acid repeat sequences, Dr Jeffreys created the ability to perform human identity tests. ( tush Butler, 2005) Sir Alec John Jeffreys, was born 9 January 1950 at Oxford in Oxfordshire. He is a professor of patrimonials at theUniversity of Leicester, and he became an honorary freeman of the City of Leicester on 26 November 1992. (Leicester City Council, 1992) In 1994, he was knighted by her Majesty Queen Elizabeth II of the United Kingdom, for Services to acquaintance and Technology.Jeffreys had a eureka moment in his lab in Leicester later on looking at the X-ray film image of a desoxyribonucleic acid experiment at 905 am on Monday 10 kinsfolk 1984, which unexpectedly showed some(prenominal) similarities and differences between the desoxyribonucleic acid of different members of his technicians family. (BBC Radio, celestial latitude 9, 2007) in spite of appearance round half an hour, he realized the possible scope of deoxyribonucleic acid fingerprinting, which uses variations in the genetic code to identify individuals. The method has become pregnant in forensic science to assist police detective work, and it has also proved useful in resolving paternity and immigration disputes. (BBC Radio, December 9, 2007) The method feces also be applied to non-human species, for example in wildlife population genetics studies. Before his methods were commercialized in 1987 his laboratory was the that center carrying come in deoxyribonucleic acid fingerprinting in the world, and during this period of about two or three years it was very busy, receiving inquiries from all over the globe. (Neston, Giles February 2, 2004) The technique utilise by Dr Jeffreys to examine the VNTRs was called restriction fragment length polymorphism (RFLP) because it involved the use of a restriction enzyme to cut the regions of desoxyribonucleic acid surrounding the VNTRs. This RFLP method was first use to help in an English immigration case and shortly thereafter to solve a duple homicide case. Since that age, human identity testing using deoxyribonucleic acid typing methods has been widespread. The outgoing 25 years have seen tremendous growth in the use of desoxyribonucleic acid enjoin in crime scene investigations as thoroughly as paternity testing. Today over 100 public forensic laboratories and several dozen private paternity testing laboratories conduct hundreds of thousands of deoxyribonucleic acid tests annually in the United States. In addition, most countries in atomic number 63 and Asia have forensic desoxyribonucleic acid programs. The number of laboratories around the world conducting DNA testing will observe to grow as the technique gains in popularity within the law enforcement community. (John Butler, 2005)How DNA Typing Is DoneOnly tenth of a single percent of DNA (about 3 million bases) differs from one person to the next. (profit character reference www.ornl.org, 2009) Scientists gouge use these variable regions to generate a DNA visibleness of an individual, using samples from blood, bone, hair, and other body tissues and products. In criminal cases, this generally involves obtaining samples from crime-scene evidence and a suspect, extracting the DNA, and analyzing it for the presence of a set of precise DNA regions (markers). Scientists find the mar kers in a DNA sample by designing small pieces of DNA ( tests) that will each seek out and bind to a complementary DNA sequence in the sample. A series of probes bound to a DNA sample creates a typical pattern for an individual. forensic scientists compare these DNA writes to determine whether the suspects sample matches the evidence sample. A marker by itself usually is not unique to an individual if, however, two DNA samples are alike at four or five regions, odds are great that the samples are from the same person. If the sample profiles dont match, the person did not contribute the DNA at the crime scene. If the patterns match, the suspect may have contributed the evidence sample. While there is a take chances that someone else has the same DNA profile for a particular probe set, the odds are exceedingly slim. Many judges consider this a matter for a jury to take into consideration along with other evidence in the case. (Internet artificial lake www.nfstc.org, 2009) Experts point out that using DNA forensic technology is far superior to eyewitness accounts, where the odds for counterbalance identification are about 5050. The much probes utilize in DNA abstract, the greater the odds for a unique pattern and against a coincidental match, but each additional probe adds greatly to the time and expense of testing. Four to six probes are recommended. Testing with several more probes will become routine, observed John Hicks (Internet Source www.alabany.edu/nerfi, 2009). He predicted that DNA chip technology will enable much more rapid, bum analyses using many more probes and raising the odds against coincidental matches.Types of DNA TechnologiesRestriction Fragment Length Polymorphism RFLP is a method employ by molecular biologists to follow a particular sequence of DNA as it is passed on to other cells. RFLPs can be used in many different settings to accomplish different objectives. RFLPs can be used in paternity cases or criminal cases to determine t he witnesser of a DNA sample. RFLPs can be used determine the disease placement of an individual. RFLPs can be used to measure recombination rates which can go bad to a genetic map with the distance between RFLP loci measured in centiMorgans. (Internet Source www.bio.davidson.edu, 2009) Total DNA is first extracted from the microbial community and the16S rRNA geneis amplified from samples using fluorescent fixturely-labeled forward and reverse primers. Next, the PCR product is purified and subjected to restriction enzyme digestion with enzymes that have 4 base pair recognition sites. This step generates fluorescently-labeled terminal restriction fragments. The digested products are then separated and detected on an appropriate electrophoresis platform. For a given sample the terminal fragments will contain a fluorescent label at the 5 end and will therefore be detected. The output will be a series of peaks (fragments) of various sizes and high gear that represents the profile of that sample. (Osborn, A. M., Moore, R.B. and Timmis, K.N., 2000)Polymerase chain reaction PCR is used to make millions of exact copies of DNA from a biological sample. DNA amplification with PCR allows DNA abbreviation on biological samples as small as a few skin cells. A polymerase is a naturally occurring enzyme, a biological macromolecule that catalyzes the constitution and repair of DNA (and RNA). The technique was made possible by the uncovering of Taq polymerase, the DNA polymerase that is used by the bacterium Thermus auquaticus that was discovered in intense springs. This DNA polymerase is stable at the high temperatures need to perform the amplification, whereas other DNA polymerases become denatured. Since this technique involves amplification of DNA, the most obvious employment of the method is in the detection of minuscule amounts of proper(postnominal) DNAs. This is eventful in the detection of low level bacterial infections or rapid changes in transcription at the single cell level, as well as the detection of a specific individuals DNA in forensic science. It can also be used in DNA sequencing, screening for genetic disorders, site specific mutation of DNA, or cloning or subcloning of cDNAs. (Internet Source www.plattsburgh.edu, 2009)Short tandem repeat STR technology is used to evaluate specific regions (loci) within nuclear DNA. Variability in STR regions can be used to distinguish one DNA profile from another. The Federal Bureau of Investigation (FBI) uses a quantity set of 13 specific STR regions for CODIS. CODIS is a bundle program that operates local, state, and national databases of DNA profiles from convicted offenders, undecided crime scene evidence, and scatty persons. The odds that two individuals will have the same 13-loci DNA profile is about one in a billion. (Internet Source www.ornl.org, 2009) The Federal Bureau of Investigation (FBI) has chosen 13 specific STR loci to serve as the standard for CODIS. The purpose of establishing a core set of STR loci is to ensure that all forensic laboratories can establish uniform DNA databases and, more importantly, share worthy forensic information. If the forensic or convicted offender CODIS index is to be used in the investigative stages of unsolved cases, DNA profiles must be generated by using STR technology and the specific 13 core STR loci selected by the FBI. (Internet Source www.dna.gov, 2009)Mitochondrial DNA analysis mtDNA can be used to examine the DNA from samples that cannot be analyzed by RFLP or STR. Nuclear DNA must be extracted from samples for use in RFLP, PCR, and STR however, mtDNA analysis uses DNA extracted from another cellular organelle called a mitochondrion. (Internet Source www.fbi.gov, 2009) While older biological samples that overlook nucleated cellular material, such as hair, bones, and teeth, cannot be analyzed with STR and RFLP, they can be analyzed with mtDNA. In the investigation of cases that have gone unsolved for ma ny years, mtDNA is extremely valuable. (Internet Source www.dna.com, 2009) All mothers have the same mitochondrial DNA as their offspring. This is because the mitochondria of each new embryo come from the mothers egg cell. The fathers spermatozoan contributes only nuclear DNA. Comparing the mtDNA profile of unidentified remains with the profile of a probable maternal relative can be an important technique in missing-person investigations. (Melton, T. et. al., 2001)Y-Chromosome Analysis The Y chromosome is passed directly from father to son, so analysis of genetic markers on the Y chromosome is especially useful for follow relationships among male persons or for analyzing biological evidence involving multiple male contributors. Y chromosome analysis is a useful technique for analyzing DNA that can be likened in one sense to translateing male surnames. Think about the stylus that male surnames are passed down from one generation to another and continue on through sons. This mech anism is a simplistic representation of Y chromosomes. A son inherits a Y chromosome from his biological father and he also inherits an X chromosome from his biological mother. Conversely, a female would inherit an X chromosome from her biological mother and an X chromosome from her biological father. (Internet Source www.esploredna.co.uk, 2009) As such, when scientists study Y chromosomes, they are studying these chromosomes as they are inherited over time through males in a familial line. This type of DNA analysis has important ramifications for scientists wishing to investigate the familial ties between male members. (Internet Source www.ncbi.nlm.nih.gov, 2009)ConclusionNo field has benefited more from the tools of molecular biota than forensic science. DNA technology affords the forensic scientist the ability to eliminate individuals who have been falsely associated with a biological sample and to reduce the number of potential contributors to a few (if not one) individuals. Inc ulpations are strong evidence regarding the source of the biological sample. Today, some wrongly convicted people have been exonerated because of DNA evidence. Moreover, in casework, individuals are excluded routinely. Since the inception of forensic DNA profiling, there has been a debate in the legal setting regarding admissibility on the methods and the practices of computing DNA profile frequencies. While the scientific basis of DNA typing were sound, both the methodology and the statistical interpretations were aggressively challenged in court. The methods challenge focused on reliability and validity testing. The statistics debate focused on the reliability of the premiss of independence for applying the product rule to derive estimates of DNA profile frequencies.ReferencesButler, John Forensic DNA Typing Biology, Technology, and Genetics of STR Markers 2nd Edition 2005 Elsevier intelligenceDesert Island Discs, Desert Island Discs with Alec Jeffreys BBC Radio 4 December 9, 20 07Leicester City Council key out of persons upon whom the honorary freedom of the city has been conferred http//www.leicester.gov.uk/aboutleicester/lordmayorcivic/freeman/honorary-freemen/list-of-freemen Retrieved December 10, 2009Newton Giles, Discovering DNA fingerprinting Sir Alec Jeffreys describes its development. Wellcome Trust. http//genome.wellcome.ac.uk.doc Retrieved December 10, 2009Osborn, A.M., Moore, R.B. and Timmis, K.N. (2000). An evaluation of terminal-restriction fragment lengty polymorphism (T-RFLP) analysis for the study of microbial community structure and dynamics. Environmental Microbiology 2(1) 39-50.Journal of Forensic Science Diversity and Heterogeneity in Mitochondrial DNA of North American Populations. January 2001 46 (1)46-52. Melton T. et alInternet Source www.ornl.org 2009Internet Source www.plattsburgh.edu 2009Internet Source www.fbi.gov 2009Internet Source www.dna.com, 2009