How DNA Profiling Works – Genetics Research Example

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The paper 'How DNA Profiling Works? ' is a great example of genetics  research. DNA profiling is the term used to refer to a technique that the forensic scientists use to identify an individual with the help of his/her DNA profile. DNA profiling is also referred to as genetic typing. It is a process of obtainment, processing, and evaluation of variable number tandem repeats (VNTRs) that are unique sequences located over the loci. VNTR indicates that the number of tandem repeats varies. A DNA profile consists of an encrypted set of numbers which shows the composition of an individual’ s DNA.

Since this DNA makeup differs from one individual to another, it is a reliable means of identifying people. DNA profiling is frequently used in criminal investigation and parental testing cases. A DNA profile is necessarily created in any situation that requires the use of DNA. In a majority of cases, DNA sequences of different individuals are so similar that it is hard to detect the differences. It is only after they are processed that VNTRs create unique bands that can easily be identified.

The differences based on unique bands were discovered by Dr Alec Jeffreys in the year 1984 while he was analyzing an experiment’ s results in which he used the DNA of one of his lab technician’ s different family members (Freeman). A variety of techniques are employed in DNA profiling. Factors that help determine which technique should be used in a certain case include but are not limited to time, cost, amount of the DNA samples and their quality. Restriction fragment length polymorphism (RFLP) was the first method that was used to develop a DNA profile.

However, RFLP is not frequently used nowadays since it needs a large DNA sample and is quite time-consuming to complete; it may take up to a month. Besides, RFLP requires study of different sections of the strand of DNA so that variations can be found. This increases the chances of error and elongates the process further. Polymerase chain reaction (PCR) analysis is mostly used in DNA profiling nowadays. PCR generates a large sample for analysis by replicating DNA in a small amount in a five-minute repeating process. First DNA polymerase that is stable to heat is added.

The sample of DNA is heated at a certain temperature to separate the threads. It is cooled off and heated again to double the copies in number. Once the process is repeated almost 30 times, enough DNA is obtained to conduct further analysis on. Another technique that replicates DNA by using PCR is amplified fragment length polymorphism (AmpFLP). This technique is similar to RFLP since it employs the use of a restriction enzyme. PCR is used to amplify the fragments and gel electrophoresis is used to sort them out.

The advantage this technique offers in comparison to others is that it is cost-effective and can also be automated. However, the use of AmpFLP requires the obtainment of very high quality of samples; otherwise, it could result in errors as it usually happens with most techniques of DNA analysis.


Freeman, Shanna. “How DNA Profiling Works.” 2013. Web. 6 Mar. 2013. .
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