DNA Fingerprinting: How Chromosomes Made The Human Body

DNA forensics is a division of forensic science that focuses on the use of genetic material in criminal investigation to answer questions pertaining to legal situations, including criminal and civil cases. Through DNA testing, law enforcement officers are able to identify human remains or the individual responsible for a crime. DNA testing is a highly advanced scientific process that involves replicating the human DNA sequence to create a genetic map of an individual. Because of its reliability, DNA testing has become a significant factor in criminal cases. However, it has also been identified as having the potential to violate privacy and constitutional rights. The DNA identification process consists of five stages. These five stages

Deoxyribonucleic acid (DNA) is a chemical structure containing a base sequence. Base pairs are genetic codes made up of four chemicals (Adenine, Guanine, Cytosine and Thymine) and each sequence differs in every person. Because DNA is so complex and varies immensely in individuals, it can be used like a fingerprint, hence the name DNA Fingerprinting. DNA can be found and analyzed in blood, semen, saliva, hair and skin--even decades old if properly stored. The process takes longer than simple fingerprinting and is very expensive, but the results are almost perfect in determining identity. While these tests are very accurate, there is a 1 in 50 billion chance that two people

Later on during his investigation he realized that this variation could be used to establish the identity of a person and he then named his discovery genetic fingerprinting. Dr. Jeffreys was able to demonstrate that a genetic fingerprint is specific to each individual. Everyone have their own pattern, that pattern does not belong to any other person on earth except in identical twins. After his learnings on DNA fingerprint, Dr.Jeffreys was pushed quickly into the world of forensic science when two murders were committed not too far from the University of Leicester. Genetic fingerprinting would be used to exonerate a suspect and

He was in his lab, which is located in Leicester, when he noticed the X-ray film image from a DNA experiment. (Alec Jeffreys biography)The experiment showed similarities and differences between the DNA of several members of his technician's family. (Alec Jeffreys biography)Shortly, Jeffreys understood the possibility of DNA fingerprinting, This process uses variations in the genetic code that identify individuals.(Alec Jeffreys biography) The method he learned has proved critical in forensic science. This method is a cornerstone to things the police force accomplish. It also helps to relinquish problems involving paternity or immigration. Even in non-human affairs, Jeffreys acquired the only centre in the world, in 1987, that did DNA fingerprinting. (Alec Jeffreys biography)At the time, the centre was extremely busy and received attention from all around the world. (Alec Jeffreys biography)DNA fingerprinting was first used in 1985. Jeffreys was asked to solve a immigration problem to determine the family of a British Boy whose family was from Ghana.(Alec Jeffreys biography) The case was easily solved when the DNA results showed the boy was of close relation to the other members of the family. The family was ecstatic to get their son, all of this would not be possible if it were not for DNA fingerprinting. Fingerprinting was first used in the field of law in 1983.(Alec Jeffreys biography) Lynda Mann and Dawn Ashworth were raped and killed in Narborough, Leicestershire. (Alec Jeffreys biography)The murderer, Colin Pitchfork, was convicted and identified after a sample of his semen matched samples taken from the two deceased girls. This played a pivotal role in the identifying of a murderer. His work proved the real killer, and also saved a man who was almost falsely convicted of this murder. If it were not for Alec Jeffreys work, an innocent man would have spent his entire life

DNA profiling is a standard tool used to help with criminal investigations. This is impactful in the field of forensics to determine and identify suspects of murder. For example, almost 50 years after the crime, DNA provided evidence in the murder of Mary Sullivan by taking a sample from the nephew of the suspect in her murder. As such, it was clear the Boston Strangler was Albert DeSalvo. (Philip Bulman, February, 2014) DNA profiling is also imperative in identifying murder victims such as Kerry Graham and Francine Trimble, who became missing in December, 1978. Due to advanced knowledge in forensic science, a DNA match identified the victims in December, 2015. (Linda Williams, 2016) DNA profiling is conducted first by obtaining a DNA sample from a crime scene, suspect, victim or other evidence. The next step is to amplify sequences to make the DNA sample larger. Finally, gel electrophoresis is used to compare regions of the amplified DNA to determine which samples are from the same individual and which are unique. There are several profiling techniques such as polymerase chain reaction which targets and quickly copies segments of DNA from even minute amounts of blood or tissue. Another profiling method is short tandem report analysis which repeats short sequences of DNA to determine exact matches between relatives and unrelated individuals. As referenced above, gel electrophoresis compares fragments of DNA by separating from different sources. Lastly, there is RELP analysis

"DNA fingerprinting." The Columbia Electronic Encyclopedia™, Columbia University Press, 2017. Research in Context, go.galegroup.com/ps/i.do?p=MSIC&sw=w&u=leb32560&v=2.1&id=GALE%7CA68487596&it=r&asid=2344db37a74f7a787a06c68c231cf4bc. Accessed 28 Mar. 2017.

Before the 1980s, courts relied on testimony and eyewitness accounts as a main source of evidence. Notoriously unreliable, these techniques have since faded away to the stunning reliability of DNA forensics. In 1984, British geneticist Alec Jeffreys of the University of Leicester discovered an interesting new marker in the human genome. Most DNA information is the same in every human, but the junk code between genes is unique to every person. Junk DNA used for investigative purposes can be found in blood, saliva, perspiration, sexual fluid, skin tissue, bone marrow, dental pulp, and hair follicles (Phillips, 2008). By analyzing this junk code, Jeffreys found certain sequences of 10 to 100 base pairs repeated multiple times. These tandem repeats are also the same for all people, but the number of repetitions is highly variable. Before this discovery, a drop of blood at a crime scene could only reveal a person’s blood type, plus a few proteins unique to certain people. Now DNA forensics can expose a person’s gender, race, susceptibility to diseases, and even propensity for high aggression or drug abuse (Phillips, 2008). More importantly, the certainty of DNA evidence is extremely powerful in court. Astounded at this technology’s almost perfect accuracy, the FBI changed the name of its Serology Unit to the DNA Analysis Unit in 1988 when they began accepting requests for DNA comparisons (Lewis, 1989).

DNA, Deoxyribonucleic Acid, is the basic structure for all life, it is the blueprint, the instruction manual, on how to build a living organism. DNA is made up of four nitrogen bases, adenine, thymine, cytosine, and guanine which are connected by sugar-phosphate bonds. Through a process called Protein Synthesis, the nitrogen bases are the code for the creation of amino acids. Essentially, DNA makes amino acids, amino acids make proteins, proteins make organisms. This process has been taking place for much longer than scientists have been able to document. Those scientists are called geneticists and their field is genetics.

Through DNA analysis the individual fragments of DNA can be separated by electrophoresis to produce the distinct DNA fingerprint. Electrophoresis separates molecules by their size through the use of an electric field, which catalyzes the migration of molecules at a rate and distance dependent on their size. In gel electrophoresis agarose gel is used to allow the DNA molecules to travel down each band. Electrophoresis allows for the fragments to be measured. The genotype at a particular locus can be determined by measuring the length of the fragments and analyzing the number of repeats. Forensic scientist as a crime scene can take samples of DNA found, such as blood or hair, and separate the fragments using gel electrophoresis. Every human as a unique DNA so each human’s DNA would show different migratory lengths when separated through electrophoresis. Thus, a comparison of the fragments for each of the suspects to the DNA fragments of the samples found at the crime scene would be able to reveal which genotype, suspect, was at the scene. This is determined by examining which DNA is an exact

    DNA F&P was invented by a man that goes by the name Alec Jeffreys. He was a British geneoligist. This process is called fingerprinting because it is highly unlikely for two people to have is for them to be identical  twins. DNA is a molecule that creates strands. These strands meld into one another creating DNA. DNA is the genetic makeup of every human being on the Earth. Currently there are 7.5 billion people here in the world. That’s a lot of DNA. This is

DNA is a long curved structure, made up of pairs of four specific bases: adenine, guanine, cytosine, and thymine, is the repository of a code from which all of our cells are made. The code is made up of base pairs which look like the

The concept of genetic profiling through fingerprints was first introduced in the 1980’s (Paul Johnson, Robin Williams, 2006). While at first it was primarily carried out on high-profile cases, most modern crime investigations use some form of genetic identification technique. The technology behind DNA identification has been rapidly growing. Instead of

All living organisms, from amoebas to humans, have a molecular code called DNA in their cells, which instruct the activities that keep the organism alive. DNA is made up of long, twisted strands of four molecular “letters” (A, T, G, and C), which pair up according to their complementary base pairs, and their order determines how proteins — the vital molecules that perform all the major tasks in our cells — are made. (Refer to Diagram 1 to help sum up the concept.)

Deoxyribonucleic (DNA) is the molecule that hold the genetic information of living things. In our body every cell contains about 2 meters of DNA. DNA is copied every time a cell divides. Deoxyribonucleic (DNA) is made up of two polynucleotide strands. Polynucleotide strands twist around each other, forming a shape that looks like a ladder called a double helix. The two polynucleotide strands run antiaparallel to each other with nitrogenous bases this means that the stands run in opposite directions, parallel to one another. The DNA molecule consists of two backbones chains of sugars and phosphate groups. The organic bases held together by hydrogen bonds. Although bases bonded together are termed paired

DNA fingerprinting is a scientific technology involving the extraction, replication and arrangement of strands of an organism’s DNA. This results in the formation of a genetically distinctive fingerprint that is unique to the organism which the DNA sample was originally extracted from. Because of the specificity of a DNA fingerprint, the application of this technology can have a substantial influence on many aspects of society. Accessibility to a DNA database allows for higher efficiency in forensic investigations, personal identification, maternal and paternal testing. The availability of a national database to police officers and forensic scientists would equate to increased productivity in investigations and prosecution of suspects in a