DNA profiling is basically a process by which certain DNA pattern, known as the Profile is collected from a person or a tissue sample.
Despite the fact that we all have our unique DNA, similarities might occur between two individuals. However, in some region, the disparities between the DNA of different people are very high; this is basically referred to as polymorphism. Every human on the planet inherited a unique pattern of polymorphisms from their parent. The DNA polymorphism is what is analyzed to gain insight into a given DNA profile.
The human DNA profile can be used in identifying the source of a DNA that is found at a crime scene or to test if two people are related. Below are some of the ways DNA profiling is used today.
- To identify the origin of body fluid that is found at a crime scene.
- To determine if two people are related
- To identify accident or disaster victims
In recent years a lot of people who were convicted of crimes they did not commit have been released. This is possible because of the DNA profiling. And it is been used in practically every industry today. For other uses on DNA profiling, such as in healthcare, you can read here: http://www.mapmygene.com/services/disease-susceptibility-test.
Short tandem repeats
The current techniques used in DNA profiling involve the use of polymorphism that is known as short tandem repeats. The Short tandem repeats is a region that consists of non-coding DNA that has repeats of the same nucleotide. The STRs can be found at different locations in the genetic loci in the DNA of a person.
DNA profile- what is it?
One of the most effective ways to produce a DNA profile is through the examination of STRs at ten or more genetic loci. These loci are usually located on different chromosomes.
A DNA profile can provide insight in determining if a DNA sample is a male or female, it can also tell who a particular genetic sample belongs to.
Next, we are going to discuss the step by step method on how you can create a DNA profile through the use of STR.
Find a sample of DNA
DNA can be found in most of the cells in the body, including semen, body tissue and the white blood cell. DNA traces can also be gotten from body fluids like sweat and saliva. DNA can be found in the saliva as well as in body fluids because they contain epithelial cells.
At a crime scene, police officers and forensic scientists collect samples of DNA so as to locate a suspect. DNA can also be collected directly from a person’s mouth through the use of a mouth swab which is able to collect the cells in the inner cheeks.
Extracting the DNA
Basically, DNA is wrapped by a nucleus of cells. In order to extract the DNA, you have to break these cells through the use of certain chemicals. When this is done, you will be able to isolate the DNA from other cell components.
Copying the DNA
Most of the time only a very small amount of DNA is available for forensic analysis, so PCR is used to get enough DNA to make a complete profile.
Find out the size of the STRs
The size of the STRs is determined through the use of a genetic analyzer.
Check if there is a match.
The number of times a sequence is repeated in an STR is calculated to determine the size of the STRs. You can use the information from this to determine if a tissue sample is from a particular person.