why use dna fingerprinting?
489427
Every person in the world has unique genetic code.  This code is present in all cells.  So if criminals are arrested and their genetic fingerprints put on record, then if they commit another crime, they can be identified by any blood, saliva, etc. that they leave behind.  That way, we're not limited by needing to get an actual thumbprint on the scene of the crime - any bodily fluid or tissue will do.  And the genetic match, if done right, is extremely accurate.
944540
Probing is based on hybridization techniques.  \n\nIf you will allow, I will describe some of the basics in this commonly used assay.\n\nLet's say, for example that you wanted to know if a genome from a particular person contained a mutation.  And that you already knew what the mutation sequence was.  \n\nYou would purchase an probe (a short stretch of DNA that would be at least 20 bases long, that's been modified with a indicator molecule) in the anti-sense sequence of what your probing.  \n\nIn theory, when the anti-sense sequence (or more commonly called the probe), finds its sense sequence, it will bind to it match (this is the hybridization step).\n\nThe indicator molecule that is co-valently attached to the probe would be something like a radio-isotope, or a fluorescent molecule.  It is used to visually indicate that the probe has, indeed, found it's complimentary sequence.  \n\nWhere the hybridization takes place has changed through out the years.  \n\nClassically the assay was performed in an agarose gel, where the DNA would travel according to its size.  Then the probe would be washed over the agarose gel, and allowed to hybridize to the genomic DNA.  \n\nI never did it this way (so I may be missing a step).  I did mine on glass slides.  \n\nThere a lot variations on this step.  Some where the probe is immobilized and fixed in location, and some where the "test" DNA is immobilized and fixed in location.\n\nIt is improtant to know which one is immobilized. Because then you know which way to orient things. \n\nAlso it is really important to control the salt concentration during the hybridization step. A high salt concentration (along with other factors like low temperature, pH) encourages DNA (probe and "test" DNA) to bind together.  I'll say it again:  High salts encourage specific hybridization to occur.\n\nDuring this hybridization step, you'll also be adding an enzyme which will co-valently (and permanently) bind the probe to the DNA.\n\nAfter a good amount time, allowing for hybridization and co-valent attachment to occur, you'll do some wash steps.  The wash steps remove any unbound probe (the probe is always added in huge amounts compared to your "test" DNA) from the assay.  \n\nThis step is also critical, because it will allow you to "read" the final results with greater acuity.  In other words, you'll have less false positive results.\n\nThe wash steps are done with lower salt concentrations.  Just the opposite of the hybridization step, with the goal of removing any probes that have inadvertently attached to the "test" DNA imperfectly without co-valent attachment.\n\nNow its time to read the results. The "read out" method is based on the molecule you attached to your probe. So if you had a fluorescent probe, you will use a fluorescent reader.  If you chose an isotope, you'll use a radio-graphic technique.\n\nEarlier I mentioned this example would be a method to detect a mutation in the genome of a patient (but you vary this method to detect a lot of different things).  So if you saw something "glowing" in your read out, then you could assume that the patient had the mutation.  If you saw no "glow" then you could assume the patient did not possess the mutation.\n\nIn reality, when one visualizes a positive result, they usually follow it up with a more sensitive test.  \n\nProbing nucleic acids is a quick way to screen for one thing on many samples. \n\nBut it can be a good way to probe one sample for many different things.  You would be limited by how many unique indicator molecules you can have (and afford) to have on your many probes that would give you unique signal.\n\nI had fun thinking about your question.  Please pass on the good Karma!
274016
Without doubt DNA - (de-oxy-ribo-nu-cleic-acid) has become the greatest aid to police investigation since the formulation of finger-printing.  Not only does it prove beyond doubt that a person was responsible for a crime but more importantly it can prove that the suspect is innocent.  Only the tip of the iceberg has been touched so far and the process will continue to become even a greater aid in the future.  Air samples from the scene of a major crime will in the future be able to be analyzed and DNA extracted from the air.   As the National Data-base for DNA gets larger there will be no hiding place for those responsible for some of the most serious crimes that are currently hardest to prove.
69828
"If performed correctly, DNA testing becomes a powerful and impartial tool, able to correctly identify any perpetrator in crimes where there is relevant biological evidence. As the technology advances and is applied in appropriate cases before trial, the chances of convicting an innocent person, at least where identity can be proven through biological evidence, is greatly diminished."
245105
They check fingerprints against many databases, including the FBI.  They also check other domestic databases as well as some foreign and international databases.
90735
Fingerprinting >\n\nn : The procedure of taking inked impressions of a person's fingerprints for the purpose of identification.
104426
DNA is a good source of evidence for forensic experts, for doctors to identify cancer, recently used for SARS detection, to name a few .\n\nThere are techniques which are used to detect the presence of a specific sequence in a given DNA sample. PCR  or Polymerase Chain Reaction is one of them. here we amplyfy a specific sequence of DNA of interest. if the biological sample contains that DNA sequence then its amplified and can be visualized on a electrophoretic gel. DNA being negativey charged runs on an agorose gel under electric current towards the positive electrode and gets separated based on the size...slower the movement the bulkier the fragment. \n\nforensic experts use this to match DNA samples from site of crime to the suspect. this can also be used in case of paternity disputes, to detect the predisposition of a person to cancer etc etc.\n\nthere are many more techniques which you can search
259889
The only down side I could possible see would be one of privacy - what are they going to do with YOUR data?  What if they store it away and 10 years from now science isolates a gene for the onset of some awful disease - and somehow your DNA shows up in some database somewhere as having this and medical insurance company gets ahold of it and drops you... same with your life insurance because of a "pre-existing condition"...  Not that this hasn't probably been taken care of by the researcher's lawyers.  Also, this wouldn't stop me from participating.\n\nThis is actually a facinating topic.  I have often thought this sort of study would be especially good for the African decendents outside Africa compared with those in Africa - this would be interesting since a great many African-Americans and -Europeans ancestors were victims of the slave trade and would have no means to trace their ancestory.  At least if they can isolate certain genes, they could find the areas their ancestors may have been from.
527242
no use....u will not be able to trace real identity...in 99 % cases. People are afraid to expose themselves.\n\nBut if really want to know then mail me ,,,i can tell u procedure. But for reaching page profile.
722412
The dual utility of DNA fingerprinting for the prosecution and the defense actually surfaced at its first use in police work. In 1986, two years after the technology was invented by Alec Jeffries of Leicester University in the United Kingdom, a girl was raped and murdered several miles from Jeffries's laboratory. \n\nA suspect confessed to the crimes, but denied a previous, similar crime. A DNA test confirmed that denial -- and when the police DNA-tested evidence from the recent murder, they discovered that the suspect's DNA was similarly absent. The suspect, once confessed but twice innocent, walked free. With both crimes now unsolved, the police found a pretext to collect blood from local men and eventually found and nailed a man whose DNA appeared at both crime scenes. "It was an extraordinarily auspicious beginning...," wrote Harlan Levy, a former New York City prosecutor. "In its first known application to a murder case, DNA testing fulfilled both its promises, clearing an innocent man and helping convict a guilty one." \n\nDNA fingerprinting was a whole lot less decisive in the O.J. Simpson case: The ex-footballer walked on double murder charges, even though his blood was found in compromising situations. The jury decided that the DNA evidence was tainted by police misconduct. While the DNA was neither convincing nor convicting, the Simpson trial forever changed the legal treatment of DNA: \n\nThe procedures for collecting and processing DNA have been tightened. With the tests considered unassailable, proper handling of evidence is crucial. \n\nJudges and juries know the basic science of testing -- or at least accept its scientific validity. George Gaucys, HLA/paternity laboratory manager at the American Red Cross in Madison, Wis., says, "There's less need to testify," in the 700 or so paternity cases his lab handles each year. (DNA fingerprinting is used to prove paternity so states can prod fathers to fund their children's upbringing.) \n \nDNA fingerprinting and the databases needed to take maximum legal advantage of them do raise privacy and ethical concerns. Some observers fear any misuse of the FBI's national DNA database, the Combined DNA Index System (CODIS). "These are technologies in which powerful organs in society control members with less power," Philip Bereano, a director of the American Civil Liberties Union, told Time in 1999 (see "DNA Detectives" in the bibliography). "They are inherently violative of civil rights." CODIS went online in 1998, offering access to state data on DNA related to rape, murder and child abuse. \n\nAnd that's fine with prosecutors, who note that given the difficulty of preventing repeat crimes by sex offenders, and the gravity of rape and murder, databases are the fastest, best protection for the public. \n\nBeyond political and legal acceptance, the increasing use of DNA fingerprinting reflects the introduction of a faster, cheaper and better technique that can produce a conviction from a pin-head size drop of blood. In fact, even a few skin cells may do the trick. Says Laber, "We've had good luck with cigarette butts, stamps, envelopes, ski masks, even a hat band. If you lose a hat or an article of clothing, there's a reasonable chance" your skin cells may be found on it.
276127
any biological item has DNA,hair,saliva,blood- doesnt take much to capture a dna sample
1151978
Try this\nhttp://www.globalonlinesvcs.com/DNA_Testing.html
622446
"DNA fingerprinting" or DNA typing (profiling) as it is now known,was first described in 1985 by an English geneticist named Alec Jeffreys.Dr, Jeffreys found that certain regions of DNA contained DNA sequences that were repeated over and over again next to each other.He also discovered that the number of repeated sections present in a sample could differ from individual to individual.By developing a technique to examine the lenght variation of these DNA repeat sequences,Dr. Jeffreys created the ability to perform human identitiy tests.\nThese DNA repeat regions became known as VNTRs,which stands for variable number of tandem repeats.The technique used by Dr.Jeffreys to examine the VNTRs was called restriction fragment lenght polymorphism (RFLP)because it involved the use of a restriction enzyme to cut the regions of DNA surrounding the VNTRs.This RFLP method was first used to help in an English immigration case and shortly thereafter to solve a double homicide case.Since that time, human identity testing using DNA typing methods has been wide spread.\nIn general, our knowledge of the origin and biological function of tandem repeats is still rudimentary. Attempts have been made to collect and systematically store in databases various information on tandem repeats. The mini-satellite database (http://minisatellites.u-psud.fr/) collects and stores short tandem repeats of a certain number of species, computed with the Tandem Repeats Finder tool. A more specialized STDR database Short Tandem Repeat DNA Internet Database (http://www.cstl.nist.gov/biotech/strbase/) focuses on short tandem repeats involved in genetic mapping and identity testing. The Tandem Repeat Data Base (http://tandem.biomath.mssm.edu/cgi-bin/trdb/trdb.exe)(TRDB) is an integrated web-based environment that allows to compute, store and manipulate tandem repeats (comparison, forming clusters, displaying statistics), as well as some other types of repeats.
839663
In the forensics field, the fingerprint is used to determine a person's identity. When they have a sample, they or the computer selects atleast 10-14 different points of reference (dots, bifurcations, islands, terminations, etc) and they compare them to the sample in question. If youre speaking in terms of practical use, the human finger is capable of sensing a difference of about 1000th of an inch. (When running it along a "smooth" surface). And I would have to agree that it does give the finger some grip. Almost like a tire. When we grip something wet, the grooves move the liquid away so you can grip it better. Id have to agree.
778914
Well, DNA can be found anywhere where cells are present.  This could be in the form of skin, tissue, blood, other body fluids.  One thing to take note of is just because cells are present doesn't mean you neccessarily have  DNA because DNA can degrade over time and depending on other circumstances such as temperature.   Once a substance presumed to contain DNA, the DNA would be isolated via a procedure.  The DNA may also be amplified with a PCR machine.  This DNA would then be compared to the suspect's DNA (which would be obtained through a blood sample or saliva).  It is a very complicated process and takes a lot longer to get a result than what you would see on CSI
60205
every person on earth has different fingerprints.  no person is going to have fingerprints that match anothers.\n\nfingerprints are made during pregnancy while the fetus in in the uterus.  as the baby is growing, it presses up against the wall of the uterus.  this pressure when it is on the fingers helps create these fingerprints.  as the baby develops, the lines are formed.  combining the pressure on the fingers and the lining of the uterus which has its own "lines", it creates fingerprints.  the differences are caused by the motion of the fetus during pregnancy and the pressure up against the "lines" as i'm calling it.  since it is impossible in a practical sense for two people to have the exact same movements within the uterus and the lining of the uterus to be the same, it is extremely unrealistic to say that two can have the same fingerprints and therefore, people can be identified by these marks.\n\nhope that helps...
238934
I know you can use saliva or blood.  Although, this is kind of hard to test for without the person knowing.  I have done a lot of research in this subject.  Any type of DNA sample works, it is just a matter of how much you are willing to pay to find out this information.  Urine is the cheapest at about $20 for a test.