Gene+Profiling+-+Fingerprinting

While most people have fingerprints, there are very rare cases where some are not able to leave traces on glass, bottles or anything. They do not have any fingerprints. In large corporations and the likes, this genetic disorder would make security a large problem for the people. Go to the links for more information.

There are also cases of schools being able to fingerprint the students without parental consent. This is an extremely controversial topic which delves into a violation of human rights.

[|Article on woman with no fingerprints]

[|Schools can fingerprint children without parental consent]

Identification need not be from fingerprints. DNA can be used to match suspects to crimes, for example. DNA is in our hair, skin, saliva, semen, and blood... Forensic DNA analysis can help solve crimes.

[|Forensics and DNA] In the example shown above, DNA collected at the scene of a crime is compared with DNA samples collected from 4 possible suspects. The DNA has been cut up into smaller pieces which are separated on a gel. The fragments from suspect 3 match those left at the scene of the crime, betraying the guilty party.
 * [[image:http://www.thenakedscientists.com/HTML/uploads/pics/dalya8_forensic_fingerprint.jpg link="http://www.thenakedscientists.com/html/Columnists/dalyacolumn8.htm"]]

-Montanna Cheng**

__DNA profiling... what is it??__ All humans have very similar DNA, and what makes each human unique only changes the DNA slightly. Most of our DNA is for representing basic traits, that make each person human, such as we have arms and legs instead of fins. but other parts of the DNA are what make up the traits that make each human unique. These fragments are called polymorphic fragments, because they vary from person to person. so basically, Gene profiling is separating the polymorphic fragments from the common fragments of DNA every human has. __What is it used for?__ Gene profiling can be used in solving crime, particularly in rape, and also in finding out who is the father/mother of a child.

__How does it work?__

To do Gene profiling, you need a fairly large amount of DNA, which can be taken from almost any type of tissue (hair,skin, blood,seimen) the sample must be fresh, or the results may not be clear. The DNA then undergoes a process called Gel electrophoresis. Broken down, all this technique does is seperate DNA molecules based on size. In order to do that though, you must seperate the different sized DNA molecules into fragments using restriction enzymes, which cut up the DNA strands. The DNA is then mixed in a buffer solution, and placed in wells in a gel, such as agar. The gel is then put in a buffer bath, in which electrical current is applied. DNA, being a negatively charged molecule do to the phosphates in its structure is attracted to the (+) electrode. The DNA will seperate into bands while it travels down the agar to the electrode, this is because it is seperated by two forces: charge, and mass. The buffer solution creates molecular friction with the DNA as it travels to the electrode, therefore, smaller molecules will travel faster due to less friction. Size of the DNA molecule also matters, as the gel acts like a sieve. Smaller molecules are able to travel faster through the solid gel, while larger molecules have a harder time fitting between the smaller spaces. These two forces seperate the DNA into distinct bands. In order to see the clear DNA however, the gel is taken out of the buffer solution and placed in a methlyn blue or CarolinaBlu solution in order to stain the DNA. The end product is a clear image of colored DNA bands seperated by size (see below)

-**Sean Murray**

__Problems with DNA Fingerprinting:__ The probability of a DNA fingerprint belonging to a specific person needs to be reasonably high--especially in criminal cases, where the association helps establish a suspect's guilt or innocence. Using certain rare VNTRs or combinations of VNTRs to create the VNTR pattern increases the probability that the two DNA samples do indeed match (as opposed to look alike, but not actually come from the same person) or correlate (in the case of parents and children).
 * 1. Generating a High Probability**

__//A. Population Genetics//__ VNTRs, because they are results of genetic inheritance, are not distributed evenly across all of human population. A given VNTR cannot have a stable probability of occurrence as it will depend on an individual's genetic history. The difference in probabilities may be because of different races. For example, some VNTRs that occur frequently among Hispanics may not appear among Caucasians. However, there is limited information about VNTR frequency distributions among ethic groups to determine an accurate probability for individuals of a particular group. Further experimentation in this area is known as population genetics, a particularly controversial topic because identifying people through genetic differences among racial lines could provide a basis for racial discrimination.
 * 2. Problems with Determining Probability**

__//B. Technical Difficulties//__ Errors in the hybridization and probing process must also be factored into the probability, and often the idea of error is simply not acceptable. Most people will agree that an innocent person should not be sent to jail, a guilty person allowed to walk free, or a biological mother denied her legal right to custody of her children, simply because a lab technician did not conduct an experiment accurately. When the DNA sample available is minuscule, this is an important consideration, because there is not much room for error, especially if the analysis of the DNA sample involves amplification of the sample (creating a much larger sample of genetically identical DNA from what little material is available), because if the wrong DNA is amplified (i.e. a skin cell from the lab technician) the consequences can be profoundly detrimental. Until recently, the standards for determining DNA fingerprinting matches, and for laboratory security and accuracy which would minimize error, were neither stringent nor universally codified, causing a great deal of public outcry.

[|Problems with DNA Fingerprinting] -**Montanna Cheng**

DNA fingerprinting is a procedure that is done in six steps. 4-5. Probing. The nylon membrane soaked with probes bind to target DNA so that fragments are detected. 6. DNA fingerprint. The final DNA fingerprint is built by using several probes. This is sent for computer analysis.
 * Making DNA Fingerprints!**
 * 1) Isolation of DNA. DNA samples are taken from cells or tissue of the body. Only a small amount is required. It can be taken from blood, hair or skin.
 * 2) Extraction of DNA. Special enzymes called restricted enzymes are used to cut the DNA at specific places. These fragments are sorted according to lengths by electrophoresis. Electrophoresis is a process whereby electrical charges are used to separate different DNA fragments according to size.
 * 3) Transfer of DNA to nylon. The distribution of DNA pieces is transferred to a nylon sheet by placing the sheet on the gel.

· Diagnosis of inherited disorders · Developing more cures for inherited disorders · Forensic or criminal · Personal identification More information at : [|**http://www.extension.iastate.edu/Publications/NCR550.pdf**]
 * __Various uses of DNA fingerprints__**
 * -Li Ying Tay**

DNA profiling has become incresingly poular among agencies around the world and especially in the "Innocence Project." The Innocence project is a public policy organization dedicated to exonerating wrongfully convicted people through DNA testing and reforming the criminal justice system to prevent future injustice. Over the years it has been in operation many dozens of people's lives have been saved while they have been serving time in prison for a crime they did not commit. The innocence project uses DNA fingerprinting to detect whether or not the suspect actually has the same DNA as that that may have been found at the crime scene. To date, 194 people in the United States have been exonerated by DNA testing, including 14 who served time on death row. These people served an average of 12 years in prison before exoneration and release. The Innocene Project has been a huge success over the years it has been in operation (15 years), and continues to attempt to exonerate wrongfully accused people. Without DNA fingerprinting many of the 194 people would be either dead or serving years for not committing a cime. So thank god for DNA fingerprinting.

- James McCann For more information on the Innocence Peoject. Visit: http://www.innocenceproject.org/


 * __An example of DNA profiling used in the Innocence Project:__

On August 14th, 1981 two women were raped within an hour, a man named Arthur Lee Whitfield was then accused for the crimes. The two women were asked to identify their rapists by pictures that the police had and they chose Whitfield. They had said that their rapist was clean shaven but Whitfield had a full beard, also, Whitfield's family told the court that Arthur had been at home the whole time when these women said they were raped. But, the jury didn't buy what the defendents were saying. And so he was given a 63 year sentence after he pleaded guilty for the second accusation so that he would have a lighter sentence. Later in 2003, after the Innocence project had begun, his case was taken. It was difficult for them to find any evidence but some of the evidence taken by a serologist was found taped in a notebook. The evidence was then used to prove Whitfield innocent in both cases. Whitfield had served 22 years already by 2004 in prison but was released due to the Innocence Project.**

- //Brandon Sellers//
 * For a more detailed story on Whitfield's case go to:** [|**http://www.innocenceproject.org/Content/291.php**]