DNA Typing
Home ]Up ][ DNA Typing ]Disease Diagnosis ]GM Food Testing ]


What is DNA Typing?

   DNA typing is a method of identifying individuals from the differences they have in their DNA. It is also used to determine family relationships between individuals.


   Advantages of DNA Typing     

The science of DNA typing relies on technology that allows an individual's DNA  to be examined and analyzed.  A person’s DNA is unique, no two individuals (except identical twins) have the same DNA.  Every cell in a person’s body has the same DNA. So, no matter what part of the body you take DNA from, it will always be the same.  DNA typing can be performed from many types of biological specimens including blood, saliva, sperm cells, muscle, teeth and bones. So a person’s DNA can be typed from very little tissue or body fluid. DNA typing is used for two major purposes. First, it is used to identify individuals from biological samples. This is mainly done in forensic casework, where it is possible to determine the identity of a criminal by typing the DNA left behind at the scene of the crime. The second important use of DNA typing is to determine family relationships. There are many situations when this kind of typing is needed, such as paternity testing, maternity testing, grand-parent testing, and even the identification of mutilated bodies is also done by determining family relationships. DNA typing is the best method of identifying individuals and determining family relationships because it is extremely sensitive- that is, with even a very small amount of tissue, the test can be done. It is also very accurate- it can give a test result with a very high degree of certainty. It is also very reliable- the chance of obtaining a false result can be minimized, and the chance of making an error in the conclusion can be calculated.

  How does DNA Typing work?

In the DNA typing process, a DNA banding pattern or profile of an individual is first obtained from a tissue sample. The DNA profile is observed in the form of a set of DNA bands known as ‘alleles’. Each person has a maximum of two specific alleles for a given genetic location. This DNA profile is compared with the profile

obtained from a sample taken from the scene of a crime. If the alleles in the two profiles match, then, it can be said that the sample taken from the scene of the crime came from the individual that was tested.



Copyright© 2004 Genetech Molecular Diagnostics & School of Gene Technology.