Premium Essay

Dna Testing

In: Science

Submitted By daly
Words 8205
Pages 33
DNA profiling (also called DNA testing, DNA typing, or genetic fingerprinting) is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles. DNA profiles are encrypted sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier. DNA profiling should not be confused with full genome sequencing.[1] It is used in, for example, parental testing and criminal investigation.

Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different to distinguish one individual from another, unless they are monozygotic twins.[2] DNA profiling uses repetitive ("repeat") sequences that are highly variable,[2] called variable number tandem repeats (VNTR), particularly short tandem repeats (STR)s. VNTRs loci are very similar between closely related humans, but so variable that unrelated individuals are extremely unlikely to have the same VNTRs.

The DNA profiling technique was first reported in 1984[3] by Sir Alec Jeffreys at the University of Leicester in England,[4] and is now the basis of several national DNA databases. Dr. Jeffreys's genetic fingerprinting was made commercially available in 1987, when a chemical company, Imperial Chemical Industries (ICI), started a blood-testing centre in England.[5]

1 DNA profiling process 1.1 RFLP analysis 1.2 PCR analysis 1.3 STR analysis 1.4 AmpFLP 1.5 DNA family relationship analysis 1.6 Y-chromosome analysis 1.7 Mitochondrial analysis 2 DNA databases 3 Considerations when evaluating DNA evidence 3.1 Evidence of genetic relationship 4 Fake DNA evidence 5 DNA evidence as evidence in criminal trials 5.1 Familial DNA searching 5.2 Partial DNA Matches 5.3…...

Similar Documents

Free Essay

Dna Evidence

...This increased role places greater importance on the ability of victim service providers to understand the potential significance of DNA evidence in their clients’ cases. What Is DNA? DNA, or deoxyribonucleic acid, is the building block for the human body; virtually every cell contains DNA. The DNA in people’s blood is the same as the DNA in their saliva, skin tissue, hair, and bone. Importantly, DNA does not change throughout a person’s life. The Value of DNA Evidence DNA is a powerful investigative tool because, with the exception of identical twins, no two people have the same DNA. Therefore, DNA evidence collected from a crime scene can be linked to a suspect or can eliminate a suspect from suspicion. During a sexual assault, for example, biological evidence such as hair, skin cells, semen, or blood can be left on the victim’s body or other parts of the crime scene. Properly collected DNA can be compared with known samples to place a suspect at the scene of the crime. In addition, if no suspect exists, a DNA profile from crime scene evidence can be entered into the FBI’s Combined DNA Index System (CODIS) to identify a suspect anywhere in the United States or to link serial crimes to each other. The effective use of DNA as evidence may also require the collection and analysis of elimination samples to determine the exact source of the DNA. Elimination samples may be taken from anyone who had lawful access to the crime scene and may have left biological material. When......

Words: 332 - Pages: 2

Premium Essay

Dna in Humans

...Brett Henson DNA Assignment 10/23/13 STR is an improvement over PCR because the STR are locations on the chromosome that contain short sequence elements that repeat themselves within the DNA molecule. The strands are significantly shorter than compared to the PCR which means that the STRs are much less susceptible to degradation and are often recovered from bodies or stains that were subject to extreme decomposition. This is an improvement over PCR which is found from blood semen or saliva. Also the longer strands of PCR take a longer time to retrieve a possible answer. The PCR test is considered to be an improvement over the RFLP because of a couple reasons. It takes much less time to complete, a week at most. The test can be performed with a small crime scene sample, which helps investigators who have little physical evidence. The DNA doesn’t have to be recently collected either. The PCR test can still be performed even years or decades after the fact, and still be just as accurate. This is because the PCR method involves copying the available DNA and analyzing only one specific gene. These are all improvements over the RFLP which requires many sample cells from the crime scene. The RFLP needs several strands of hair or large splatters of blood. The cells have to be “fresh”, which means undamaged and recently dead. The test takes anywhere from 3 weeks to three months to complete. Mitochondria are structures within cells that convert the energy from food into a...

Words: 525 - Pages: 3

Premium Essay

Dna Testing

...Genetic testing is currently available for more than 1000 conditions, and it is increasingly considered an integral component of mainstream health care (Burke, 2004). Furthermore, many genetic tests are now being marketed directly to consumers. The increased availability of genetic testing may result in a wider distribution of the benefits of testing, such as decreased uncertainty, the chance to avoid passing on a gene mutation to future generations, increased psychological well-being, and greater awareness of available treatments or risk-reducing strategies, but it may also contribute to an increase in the risks associated with genetic testing, such as decreased individual and family well-being; increased depression, anxiety, guilt, stigmatization, discrimination, and family conflict; and unnecessary or inappropriate use of risk-reducing options (Riper & Gallo, 2005). Money is maybe the most important driving force in the modern era of biotechnology. Genome and genetic findings have been given also financial value. The possibility to test for genetically-based individual susceptibility provides new ideas for marketable products. In an industrial worker, a metabolic polymorphism that causes an increased risk for cancer would create an avoidable financial burden in industry and insurance companies. The involvement of such financial aspects brings along several ethical implications in genetic research. The first aspect is the motivation of scientists......

Words: 2673 - Pages: 11

Free Essay

Dna Databases

...DNA Databases Alannah Beard GS1145 January 06, 2014 ITT Technical Institute Research and Essay Article This article observes the use of DNA examination in solving crimes, California’s new law Proposition 69, and how convicted serial rapist Mark Rathburns been put to a stop sooner if the DNA law had been put into place years ago. The Proposition 69 law was approved by 62 percent of California voters, which it will produce the largest DNA database in any state. What the Proposition 69 will do is allow law enforcement to collect genetic material from all convicted felons and others convicted of any serious crimes starting in 2009. The article also talks about the backlogs of samples pending investigation, the difficulties with DNA testing, and Civil Libertarians arguing that Proposition 69 is a breaching privacy and security of the people. The quality of information that was given was insightful. It brought up topics and a law that I didn’t know about. Learning about the Proposition 69 law and how it can minimize crimes is shockingly interesting. The writer certainly did her research before writing the article, and it’s good to know that there are people out there who what us to know what else is happening in the world beside other things. My opinion of the article is that DNA databases can be useful to solve crimes, but then again it would give those in power the automatic ability to take DNA from whoever they want, regardless of reasoning. Citizens should still get a...

Words: 300 - Pages: 2

Free Essay

Dna Paper

...DNA DNA or Deoxyribonucleic acid is the very building block needed in the creation of life. It is composed of genetic instruction to map out the creation of an entire organism. DNA is well suited in the storage of biological information. Yet with all of this complex information there are certain chemicals or forms of energy that can damage or alter this special coding. In process of damaging or altering the coding of DNA the most dreaded situation of a cancerous cell can be formed. To start let’s look at the different kinds of radiation that may or may not effect DNA. Alpha, Beta, and Gamma Radiation Ionizing Radiation can change the way our body’s work and develop. Direct includes covalent linkage between nitrogenous bases, and creating structure like thymine dimmers. Indirect is when it interacts with water to create free radicals which can interact with a person’s DNA. It can cause single or double stranded breaks in the sugar- phosphate backbone. (Buttons, n.d.) Alpha Radiation is a process that needs to be swallowed, inhaled, and or absorbed into the blood stream. This can increase the risk of cancer also known as lung cancer. Radon is a silent but deadly killer. To determine if one has been affected by alpha particles testing would be completed with special equipment and gear to prevent those from any exposure. Beta Particles can be a helpful process of treatment to many, such as treating thyroid disorders, cancer, and Graves’ disease (hyperthyroidism). It......

Words: 1589 - Pages: 7

Free Essay

Curry and Dna Testing

...this. On one hand I would say yes to testing their blood, as an owner of a team you’re going to be paying someone millions of dollars for a sport you should be allowed to test whatever you want. After all it is a big investment, and just like any investment you want insurance. On the other hand as a player I feel like it would violate my rights as a person if you wanted to test my blood for no reason. In Curry’s case I feel like he should have let them do a DNA test to see if their investment was a good one. I also believe some professional athletes get paid too much money for what they do. 2. I believe that negligent referral could possibly be an issue if the New York Knicks were unaware of Curry’s condition. Mixed Motive also plays a huge part in this case. I believe that since they were not allowed to take a DNA sample if his blood they had a legitimate and illegitimate reason for letting him go to another team. They already had Curry go to one of the best doctors in the world and if he cleared Curry to play and said he was fine they should have trusted the doctor they sent him to. Since he did not do a DNA test I believe they let him go to protect their investment. Also the Genetic Information Nondiscrimination Act (GINA) is an issue in this case. If they want to test Curry to see if he is susceptible for the Disease then they are in Violation of GINA. 3. In most cases I would not think it would be necessary for a company to test DNA of an Employee, but not......

Words: 550 - Pages: 3

Premium Essay

Collecting Dna

...Collecting DNA Purpose To collect separate and collect DNA from a source using common household items. Required materials • ½ cup split peas • 1/8 tsp. salt (table variety) • 1 cup cold distilled water • Blender • Mesh strainer with very tiny holes • Bowl or cup • 2 tbsp. liquid detergent • 3-4 test tubes or thin vases • Meat tenderizer or contact lens solution • Rubbing alcohol with at least 70-95% alcohol content • Wooden BBQ skewers • Journal or notebook paper • Digital camera or traditional camera (if available) [pic] Estimated Experiment Time An hour or two at most. [pic] Step-By-Step Procedure • 1. Combine the peas, salt and cold distilled water in your blender. Blend on high for at least 15 seconds but no longer than 25-30. • 2. Assemble your strainer above a bowl or cup and pour the liquid remnants of the peas from the blender through the strainer and into the cup. • 3. Stir in the liquid detergent, being careful not to over mix. Let stand for ten minutes. • 4. Fill your test tubes or thin vases about 1/3 of the way full with the pea mixture. • 5. Sprinkle just a pinch of the meat tenderizer (or just a drop or two of contact lens solution) into each test tube or vase. Stir very gently with a BBQ skewer, being careful not to over stir. • 6. Gently pour the rubbing alcohol into each test tube or vase, making sure you have about the same amount of alcohol as......

Words: 381 - Pages: 2

Premium Essay

The Use of Dna in Solving Crimes

...How DNA has changed the Criminal Justice System Information Technology in the Criminal Justice System Professor Cynthia Orth Tyrone S. Gibbs 11/21/2010 1 The use of Dna has changed the Criminal Justice System by allowing other materials beside blood to be used as identification. Before the advent of DNA testing, human identify testing was carried out mostly by using blood typing DNA analysis has now passed blood testing and is now the most accurate method currently available for human identification. DNA testing is used in determining parentage but is more widely known for the use in criminal cases. DNA testing is a powerful and reliable form of forsenic evidence that can beyond a shadow of a doubt reveal whether a person is innocence or guilt. One of the disadvantages however, is many prisoners do not have the legal means to secure testing or evidence in their cases. Some states have passed statues that include barriers to testing that are almost impossible to surpass. This is a obstacle that will keep innocent people from securing DNA test to prove their innocent. One of the advantges of DNA is that by using DNA fingerprinting is the use in solving crimes. Since DNA is found in almost every cell in the body, any portion of the human body can be used to establish identity. Just by the use 2 of a single strand of hair, a piece of skin, nail, a drop of blood or saliva can establish guilt or innoccence. Since it is impossible to remove all bodily or physical......

Words: 329 - Pages: 2

Free Essay

Clement Dna Exonerations and Race

... DNA Exonerations and Race Thomas ****** **** College Course:**** Dr. *** **** October 18, 2015 . Originally I planned on doing my paper on African Americans and the death penalty. After doing research for a few days it hit me that there was a whole other topic that I should be doing. Under most instances I support the death penalty but I came across an article that gave an opinion that all death penalty inmates should have their evidence reexamined and DNA tested if they were convicted in a pre DNA era. After that I looked into the statistics of people that had been exonerated after serving years in prison by reexamining the DNA from their cases. I was amazed that there had been so many people exonerated out with such limited resources. I now knew that I wanted to know more about DNA exonerations what the statistics were with race and those wrongfully convicted. I think the two subjects African Americans and the death penalty and DNA exonerations could be really enlightening as it shows that the American Justice System in the past surely has executed wrongfully convicted men in the past. So I used Google to search “Exonerated by DNA and Race” and began to read not only their cases but also their stories. The next day I was already questioning my stance on the death penalty. Not only did I think about how their lives will never be the same I thought about all the time they lost and can never get back. Time stood still for them while their......

Words: 648 - Pages: 3

Free Essay

Dna Role in Forensicsscience

...DNA Role in Forensics Science At a crime scene there may be a lot DNA evidence left behind or none. DNA can identify victims and suspects. It can help solve cold case and give new leads to other cases. DNA is also use to determine kinship in a missing person case. It can also help exonerate someone from a crime that they were convicted of. When handling DNA such as blood at a crime scene it is important that it is properly documented, photographed, collected and stored. Besides blood, DNA can include: body fluid, hair and skin. Such DNA can be matched to an individual. DNA is the acronym for Deoxyribonucleic acid. According to Campbell Essential Biology with Physiology, “The word nucleic is referring to “DNA location in the nuclei of eukaryotic cell.” (Page49). “DNA is genetic material that humans and other organisms inherit from their parents which consists of gain molecules” (Page 48). The shape of DNA is a double helix. Some would say it looks like a twisted ladder. “The double helix has four bases; (A) Adenine, (C) Cytosine, (G) Guanine and (T) Tyhmine. The bases have to be properly linked to their pair or else there will be a mutation in the gene. The following are the base pairs that bind:”Adenine with Tyhmine and Cystosine with Guanine” (Page 49). DNA testing began in the mid 1980’s. In the online article, DNA Factors states: Ever since the start of DNA testing in 1985, biological material has been a reliable physical evidence to help solve crimes......

Words: 2568 - Pages: 11

Premium Essay

Dna Testing

...lawfully-seized clothing and conduct a DNA test that generates a DNA identity profile. The petition explains: When the police lawfully seize a bloody article of clothing during a criminal investigation, they may wish to run a DNA test on the blood. DNA testing can reveal the DNA profile of the person whose blood was found on the clothing. The police can then try to match that DNA profile with profiles from other samples to prove identity. Lower courts have divided on whether the practice of removing blood from lawfully-seized clothing and testing it to obtain a DNA profile is a Fourth Amendment “search” of the owner’s effects. The Fourth Circuit has held that it is a search. The Maryland Court of Appeals (the state’s highest court) has disagreed. In the case below, the Massachusetts Supreme Judicial Court agreed with the Maryland Court of Appeals and disagreed with the Fourth Circuit. Shortly after we filed our cert petition, the Maryland Public Defender filed an amicus brief in support of the petition. The respondent, the commonwealth of Massachusetts, initially waived its right to file a response. The Supreme Court requested a response, however, and the commonwealth filed its brief in opposition on Nov. 20. We filed our reply brief last week. The briefs mostly focus on whether the case is cert-worthy, which is pretty technical stuff. Blog readers are probably more interested in the underlying merits: Why is blood removal and testing a Fourth Amendment search? Here’s......

Words: 561 - Pages: 3

Premium Essay

Dna Science

...DNA Replication A cell's DNA sequence contains all of the information it needs to make the molecules of life. Amino Acids help DNA to produce a cell. There are several proteins and enzymes that are involved with DNA replication, they help assemble liquids and carbohydrates. DNA replication begins with one DNA double helix and ends with two DNA double helices. At a certain point, the double helix slows down, due to the shortage in the RNA strand. That's why proteins are existing to hold the loose DNA strands in their positions. Each strand of DNA will then serve as a model to it's opposite strand of DNA. The original cell must be duplicated so after the cells have divided, so that each cell will have the exact amount of DNA. DNA replication is vital for the continuation of a species as it allows n organism to reproduce its genetic code and pass it along to the next generation. Without DNA replication, there would be no reproduction, so after all the current life dies out, there would be no more. DNA polymerase plays the central role in the activity of life. All living organisms have DNA polymerases. One enzyme does all the work. DNA polymerase carries the load of responsibility reproducing our genetic information. Every time a cell divides, DNA polymearse reproduces all of it's DNA and passes it to another cell. DNA polymerase loosens our DNA and builds a matching mate or reproduce to each strand. DNA polymerase corrects the common defects that occur in the......

Words: 393 - Pages: 2

Free Essay

Dna Sequence

...INDEX 1.To retrieve the protein or DNA sequence in FASTA format from the NCBI database and analyze the obtained data. 2.For a given protein sequences find the function ,structural relevance and annotation studies by using Uniprot/Uniprot KB. 3.For a given protein, find the protein PDB code ,release date , resolution ,Classification and pub med citation from PDB Structure data base. 4.Find the disease pathway ,drug target enzymes and drug molecules used for a given disease by using KEGG database. 5.For a given protein/enzyme find its EC number ,its location and Km, K cat/Km values by using BRENDA/KEGG database. 6.Find the pair wise sequence alignment for a given protein/DNA sequence by using Dot matrix method Dot helix and comment on the results inverted repeats ,palindromes. 7.For a given Protein sequence find the homolog sequences and Study the obtained output critical statistical parameters, the % identity, %similarity ,p ,E-value by using BLAST. 8.For a given Protein/DNA sequence find the pblast ,nblast ,psi blast ,phi blast ,blast, tbalstn and analyze the obtained results obtained results for each blast method. 9.For a given Protein sequence find the pair wise sequence alignment by using the FASTA algorithm and compare the results obtained with those from other methods. 10.Find the optimal alignment for the given protein sequence by using Dynamic programming –LALIGN method. 11.For a given FASTA sequence find the multiple sequence alignment by using the Clustal...

Words: 2349 - Pages: 10

Free Essay

Dna Overturned

...Tommie Brown Grand Canyon University The History of Criminal Investigations DNA Overturned June 29, 2016 Many cases have been solved with good investigation work and the technology of DNA. As a result of this technology many convicted criminals have been released due to DNA overturned in their cases. This was true in the case of Anthony Capozzi who spent 22 years in prison for a crime he did not commit ( In the mid-1980s Capozzi was wrongfully convicted of committing two sexual assaults in Buffalo, New York. It was DNA testing that proved his innocence ( The true perpetrator’s identity was revealed and DNA testing also revealed that this criminal committed multiple rapes and murders. The crimes itself consist of several women being raped along the bike path in Delaware Park. The crimes took place around December of 1983 and July of 1984. The attacker had it all planned out as he would wait for the right moment then move in for the attack. The attacker apparently surprised his victims from behind by threatening them with a gun. Once the victim was at his mercy he went on to rape them and when finished he gave them instructions to remain on the ground for up to 20 minutes before they move (

Words: 1161 - Pages: 5

Free Essay

Dna Testing

...Assignment: DNA Testing James Bunch CRJ311 Forensics Instructor Will Curcio April 9, 2012 This paper will compare and contrast the newest DNA-typing techniques and short tandem repeats (STRs) with previous DNA typing tests. It will detail how DNA is currently used in criminal investigations. Finally, what is the current impact of DNA testing on the criminal justice system and how has DNA revolutionized this system? In April of 1953 Dr’s Watson and Crick announced the discovery of deoxyribonucleic acid, better known as DNA. The scientific world has not been the same. Before the discovery of DNA the investigators could use blood to narrow the list of suspects. With the discovery of DNA we now have a blood “fingerprint”. Identical twins do not have identical finger prints and in some cases they do not have identical DNA (2008, Casselman). This can make the job of the investigator easier. DNA testing began with Dr. Alec Jeffery in 185 he discovered that certain places on the DNA molecule were repeated. He also found that these repeated sequences were unique to each individual. These repeated sequenced areas are known as VNTRs which is an acronym for variable number tandem repeats. The technique......

Words: 1076 - Pages: 5