All individuals have unique DNA unless they are identical twins. The process of DNA fingerprinting is a technique carried out in laboratories in order to establish an association between biological indication and a suspect in a criminal probe. A sample of DNA picked from a crime scene is matched with that of the suspect’s DNA sample. If there is a match, then evidence arrives from the suspect. If the DNA did not match, the evidence did not come from the suspect. This technique is also utilized to establish paternity and is used in other sectors too.
The DNA of every individual is 99.9% identical, however, there is a 0.1% difference between individuals. The DNA fingerprinting technique is as though a bar-code of DNA of an individual. DNA is present in each cell of an individual and is tightly associated with histone protein, they are found in every chromosome. Typing of DNA can be accomplished by using samples from any biopsy tissue of an individual’s saliva, components of blood, semen, vaginal fluid, items of personal use such as bottles, toothpicks, razors, cigarette butts, bone teeth, hair, cans or glass, clothes or any kind of biological residues could be used for the profiling.
Further, urine could also be used for the extraction of DNA from epithelial cells that is liberated from the digestive tract in the process of urination. However, recent learnings indicate that a healthy individual’s epithelial cells cannot be discharged in urination.
Aim of DNA Fingerprinting
DNA fingerprinting finds a vital application in the field of forensic science to begin. With the aid of DNA evidence, punishment to a guilty person instead of an innocent one, the objective of researching in the field to explore possibilities of other breakthroughs in the field of medical science are targeted. Another aim is to attempt to eradicate the incorrect perception of people revolving around DNA-fingerprinting, carefully carrying out DNA evidence analyzing, spreading awareness to establish a connection between analysts and people in order to enhance the methodological techniques which comprises DNA analyzing process is also the purpose.
Applications of DNA fingerprinting
The use of DNA fingerprinting is across domains. It is utilized to classify inherited diseases, in criminal investigation, identifying victims, in paternity test, genetic profiling of a person in a species, to find similarities amongst individuals of various species, determining evolutionary relationships amongst closely associated species. Further, it is also used in breeding schemes, to track threatened species, in the sex determination, conservation of biodiversity etc.
DNA Fingerprinting – Techniques
There are two types of techniques used in DNA typing –
- PCR (polymerase chain reaction) based
- Non-PCR based
The non-PCR based techniques are conventional techniques which are time-consuming, processing at slow rates, initiating good outcomes and requiring DNA samples in large quantities to analyse. PCR-based procedures, on the other hand, are quick, requiring smaller quantities of the DNA sample in order to analyse. However, there is a scope of contamination in the process of PCR amplification. An example of non-PCR based technique would be Restriction fragment length polymorphism (RFLP) while examples of PCR based techniques would be microsatellites, short tandem repeats (STRs), mini-satellite etc. This was a brief on DNA fingerprinting. Explore and learn more about related topics by subscribing to BYJU’S YouTube Channel.