1.1. Amplification
If the quantity of the DNA isolated is not enough, the specialist increases it to optimal levels via an amplification technique that uses the polymerase chain reaction (PCR) process. In addition, PCR targets specific locations on the DNA strand known as the loci (singular: locus) to produce similar copies.
1.2. Electrophoresis
In this process, the specialist separates the materials based on their size and composition of the DNA strands on a particular gel in the presence of electricity. The figure below displays the electrophoresis results (courtesy of How Stuff Works).
1.3. Analysis
The last stage involves analyzing the DNA screening results obtained based on a particular program in the National DNA Database. Short Tandem Repeats (STR) analysis dominates the process for the purpose of criminal investigations. This is because the STRs do not characterize the physical appearance of an individual. The field of forensics insists on the use of STRs because its locus is made up of two alleles.
2. Introduction
The evolution of technology brings with it unlimited significances to the modern society. Every day new technology emerges in the world to solve a particular problem. The rate at which technology influences lives seems immeasurable. In the process, the advancement in technology spreads across all professional fields linking one area of specialization to another. Initially, there existed no direct links between applied sciences such as biology and social sciences such as political science. It is because the two areas deal with distinct and diverse ideologies. Nowadays, it seems that the two cannot perform independently without each other. In one way or another, they intertwine on similar application a...
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The National DNA Index (NDIS) contains over 8,483,906 offender profiles and 324,318 forensic profiles as of June 2010 (Federal Bureau of Investigations, 2010). It has been suggested by Froomkin, a Senior Washington Correspondent, that the FBI is “shifting its resources from forensics to feeding the database” (Froomkin, 2010). This dramatic shift curtails some of the benefits of the CODIS application to the criminal justice system, as the backlogs of DNA samples increase and the statutes of limitations grow nearer and nearer on unsolved crimes.
in the sample in to many identical samples. The DNA retrieved from the reaction can then be
Deoxyribonucleic acid (DNA) is an acclaimed extraordinary discovery that has contributed great benefits in several fields throughout the world. DNA evidence is accounted for in the majority of cases presented in the criminal justice system. It is known as our very own unique genetic fingerprint; “a chromosome molecule which carries genetic coding unique to each person with the only exception of identical twins (that is why it is also called 'DNA fingerprinting ')” (Duhaime, n.d.). DNA is found in the nuclei of cells of nearly all living things.
Familial DNA searching works by using the combined DNA index system (CODIS) to compare DNA samples taken from crime scenes to DNA profiles already recorded in the local, state, or national criminal DNA database. There are many indexes in the database; two of the largest are the offender index, a catalogue of DNA profiles from previously convicted felons, and the forensic index, a catalogue of DNA from crime-scenes. A DNA sample is run through the database by CODIS’ matching algorithm that searches the indexes against one another to generate matches according to how often base pairs, or “markers,” repeat in th...
Hines, Nico. “Father of DNA evidence, Sir Alec Jeffreys, calls for database to be cut”. The Times. 10 Sept 2009. Web.
In 1989 the National Research Council Committee on DNA Technology in Forensic Science was developed due to numerous scientific and legal issues (The Evaluation of Forensic DNA Evidence). The National Research Council’s key role was to analyze statistical and population genetic issues in the use of DNA evidence and review major alternative approaches to statistical evaluation of DNA evidence (The Evaluation of Forensic DNA, 50). Over the past fifteen years DNA profiling has made tremendous advancements and continuous improvements in the fight against violent
Norrgard, Karen. "Forensics, DNA Fingerprinting, and CODIS." Nature.com. Nature Publishing Group, n.d. Web. 010 Dec. 2013. .
being the same is as low as one in a trillion. Critics of DNA say that the FBI has falsely
Ballantyne, Jack, George Sensabaugh, and Jan Witkowski. DNA Technology and Forensic Science. New York: Cold Spring Harbor Laboratory Press, 1989.
Butler, J. M. (2005). Forensic DNA typing: biology, technology, and genetics of STR markers. Academic Press.
Once a crime has been committed the most important item to recover is any type of evidence left at the scene. If the suspect left any Deoxyribonucleic acid (DNA) at the crime scene, he could then be linked to the crime and eventually charged. A suspect’s DNA can be recovered if the suspect leaves a sample of his or her DNA at the crime scene. However, this method was not always used to track down a suspect. Not too long ago, detectives used to use bite marks, blood stain detection, blood grouping as the primary tool to identify a suspect. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique it has been a la...
Prime, Raymond J., and Jonathan Newman. "The Impact of DNA on Policing: Past, Present, and
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 (Butler, 2011). 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 (Butler, 2011). 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 (Using DNA to Solve Crimes, 2014).
The scientific and medical progress of DNA as been emense, from involving the identification of our genes that trigger major diseases or the creation and manufacture of drugs to treat these diseases. DNA has many significant uses to society, health and culture of today. One important area of DNA research is that used for genetic and medical research. Our abi...
DNA fingerprinting is a process that has been subject to widespread debate ever since it has come into practise. Fingerprinting involves identifying and creating an image of a person’s genetic information. As each individual carries their own DNA fingerprint—meaning that no two will ever be the same—it is often used for identification purposes and can produce a very reliable, if not indisputable result. This makes the DNA fingerprinting very useful within the field of forensics, as well as in paternity testing and law enforcement. Despite its various uses, the debate goes on about the usage of the process. Many are concerned about their right to privacy, with DNA being an incredibly personal thing. What if the database containing this information was hacked, or forms another type of discrimination? Currently, Australia stores the DNA profiles of samples collected by the Australian police, including samples found at crime scenes, from convicted offenders, suspects, missing persons and unidentified deceased persons on the National Criminal Investigation DNA Database (NCIDD) (CrimTrac 2011). Similar databases are held around the world. Therefore, the question remains, would there be purpose in storing the DNA fingerprint of all newborn babies on a central database, to creating a database storing all of a populations genetic information, similar to that of the NCIDD?