DNA

The process of identifying DNA

All individuals, except identical twins, have unique DNA. DNA fingerprinting is an unambiguous identification method that takes advantage of the difference in the DNA sequence. This process of DNA fingerprinting starts with the isolation of the DNA from the identified sample, such as blood, saliva, semen or other body tissues. In instances where the available sample is small for the process of fingerprinting, then the sample is augmented through a process called polymerase chain reaction (PCR). PCR is the process of DNA replication that does not use living cells and, therefore, the process is appropriate in fingerprinting old samples. The focus of this process is on the short tandem repeats (STR) that have short units of DNA that are repeated several times in a row. After the DNA is isolated and amplified it is treated with restriction enzymes. This process cuts the DNA strands at definite sequences called restriction fragment length polymorphisms (RFLPs). Since everybody’s DNA is different the resulting RFLPs will be of different sizes. These fragments are observed in gel electrophoresis; a process that separates DNA based on the size of fragments. RFLP analysis is based on the fact that since everyone’s genetic sequence or the variable number of tandem repeats is different this result in the different sizes of RFLPs. Gel electrophoresis involve the separation of the fragments of DNA as they migrate through an agarose gel when an electric current is applied to the gel. The DNA that has separated is then drawn out of the gel with a nylon membrane which is treated to break the hydrogen bonds holding the DNA strands together. The separated strands of the DNA is then cross-linked to the nylon membrane a...

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...onventional techniques of establishing paternity. The use of these antigens has an 80 % effectiveness rate in establishing the paternity of a child and is, therefore, the most effective method in paternity tests. The results from tests can either be inclusion or exclusion where inclusion implies the tested an is the father while exclusion excludes the man as being the father of the child. The results of a paternity test might be significant to the court in determining child support, social welfare benefits, inheritance, adoption and immigration.

Reference list

Brown, T. (2010). Gene cloning and DNA analysis: an introduction. John Wiley & Sons.

Kobilinsky L. F., Levine L. & Margolis-Nunno H. (2009). Forensic DNA Analysis. Infobase Publishing.

Rothstein M. A. (2005). Genetic Ties and the Family: The Impact of Paternity Testing on Parents and Children. JHU Press.