How is DNA testing useful?
DNA testing also known as DNA profiling is a technique pertaining to forensic science that helps to identify and determine an individuals characteristics through the help of the DNA. Now what is the DNA profile of an individual? It is a small set of DNA that is likely to vary between unrelated individuals. It is a unique as the fingerprint of an individual. DNA testing is very different from genome sequencing. DNA testing is mostly used in crime investigation and establishing the paternity of an individual. However there are many other uses of DNA profiling as well.
How is DNA testing done?
The process of DNA testing is established by the father of genetics, Sir Alec Jeffreys. In this process, a sample of the persons DNA (called a reference sample) is collected. The most common method of collecting this reference sample is through a buccal swab is not expensive and easily available and also non-invasive. If a buccal swab is not obtainable then other samples like saliva, blood, semen, sweat and other fluid tissue are used to collect the sample. This reference sample is then analyzed to determine an individuals DNA profile.
There are different types of DNA testing:
Polymerase Chain Reaction (PCR) Analysis: the PCAR analysis produces millions of precise DNA replications even from the smallest cell. Hence it has the advantage of analyzing even the miniscule sample that is gathered from the crime site.
Restriction Fragment Length Polymorphism (RFLP): this was one the first techniques of DNA analysis in forensic science but is slowly becoming obsolete. This technique is becoming obsolete because large size of samples are needed as compared to other techniques.
Short Tandem Repeat (STR) Analysis: this technique analyses individual areas of the DNA. In criminal investigation thirteen areas are analyzed to establish DNA profiles.
Mitochondrial DNA Analysis: this technique is used for samples on which the STR or RFLP techniques fail. There are two types of DNA mitochondrial and nuclear DNA. In all the types of DNA testing the nuclear DNA is removed from the sample, but in this analysis the mitochondrial DNA is removed from the sample.
Y-Chromosome Analysis: the Y chromosome passes from the father to the son and this analysis is used to determine parental disputes.
Uses of DNA testing:
Archaeologists are now using DNA tests to record genetic codes and how life has progressed on earth that date back to centuries. DNA databases are maintained that are used to compare DNAs. DNA profiling has helped scientists to understand mutation and evolution.
DNA testing is the most definitive way of establishing a childs paternity. Either for mental peace or for legal matters often it becomes imperative to establish the father child relationship biologically. This is when DNA testing plays a huge role.
To establish a family tree and trace back to ones genetic ancestors often DNA testing is done. As the Y chromosome found in male are not likely to change from generation to generation, the analysis of Y chromosome can be done to establish family lines.
One major use of prenatal DNA testing is that it helps doctors to understand the health condition of the fetus and also diagnose any health issues. The probability of risk in certain genetic diseases is also determined with the help DNA testing.
Another wide usage of DNA testing is seen in criminal investigation. DNA profiles are stored by the police to solve cases. Often serial offenders are identified through analysis of a DNA sample.
In the wide spectrum of science DNA testing is done on new species and unidentified objects from outer space.
Many Dna testing are also done on gifted children in to identify which mixture of genes from their parents gave them their intelligence.