DNA fingerprinting

A quick look at DNA fingerprinting






DNA fingerprinting: DNA fingerprinting is a method used by forensic scientists, to aid them identify people based on their DNA profile. A DNA profile are an encrypted arrangements of numbers which identify you.

DNA fingerprinting process

There are 4 different methods used for DNA fingerprinting they are:

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  restriction fragment length polymorphism analysis: using restriction enzymes(a type of enzyme which cuts single or double layered DNA strips at specific points) the piece of DNA is cut and then, it goes through a process called southern blot, during the southern blot process it detects certain parts of a person's DNA sequence in the DNA sample.



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  polymerase chain reaction analysis: The piece of DNA is heated any where from 20 to 40 times, one of these is called a cycle. DNA melting(bonds which are made up of hydrogen are disturbed thus triggering this) occurs. They then check to see if the right DNA fragments were created.



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  short tandem repeats: is when 1 or 2 nucleotides(molecules which make up base of DNA) are replicated, and the replica's are the same.



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  amplified fragment length polymorphism: special enzymes cut the DNA in certain areas, making little bits of DNA, those bits the go through something called pre selective amplification, all this means is it betters the pieces of DNA, using another technique called polymerase chain reaction the number of bits of DNA are replicated until there is a sufficient number of them that they can be seen using a special gel, the images seen can then be compared to other pieces of DNA

History of DNA finger printing

While working in his lab one day British scientist Alec Jefferys realized that while he was observing the x ray of a DNA experiment, he realized that people are both alike and different in certain ways. Approximately half and hour passed and Alec Jefferys came to the conclusion that, DNA fingerprints gave information in regards to a person genetic coding.

Application&Uses

Although there are many uses for DNA fingerprinting only some are worth mentioning. First and foremost the most widley known use for DNA fingerprints is used in criminal justice courts. Due to the fact that DNA fingerprints are like an I.D that you have with you, you may also leave traces of it through body fluids, hair. Thus for a example a person who works in a crime lab would be able to match your fingerprint to ones found in a crime scene for example. also DNA fingerprints are used frequently in medicinal practises, using for example a babies dna fingerprints, doctors can determine whether a baby has inherited some sort of disorder or not. this can also be done before a baby is born using the parents' dna fingerprints.

Examples

• Perhaps the most famouse use of DNA fingerpinting is when Anna Anderson claimed that she was the only live survivour of the russian Czar. Although in the 1950's there was no DNA fingerprinting sometime in the 1980's it was proved that using an imprint of her fingerprint that she was in fact not the last duchess of russia.
• Colin Pitchfork was the first to be proven guilty of murder using DNA fingerprinting
• in 1991 Kirk bloodsworth was the first person to be proven innocent using DNA fingerprinting, thus escaping a death sentence

References

Information

http://www.accessexcellence.org/RC/AB/BA/DNA_Fingerprinting_Basics.php

http://en.wikipedia.org/wiki/Alec_Jeffreys


http://en.wikipedia.org/wiki/DNA_fingerprinting

http://www.bookrags.com/research/amplified-fragment-length-polymorph-wog/

Videos

http://www.youtube.com/watch?v=drC7rR7CIBg

http://www.youtube.com/watch?v=RLpalVirlTk

http://www.youtube.com/watch?v=WlAcjXtIEZc

Images

http://www.separationsnow.com/FCKeditor/UserFiles/Image/separationsNOW_ezines_2007/0703_fingerprint.jpg

http://upload.wikimedia.org/wikipedia/commons/c/c5/Alec_Jeffreys_-2008.jpg