What is DNA Fingerprinting?
DNA fingerprinting is a technique used in genetics for isolating and identifying the variable elements in the sequence of the base pair in the DNA.
DNA fingerprinting is also called out in many forms as DNA profiling, genetic fingerprinting, genotyping or as identity testing.
This technique was first developed by British Genetist Alec Jeffreys in the year 1984 when he was noticing the certain sequences in a highly variable DNA, which is also known as minisatellites, that do not contribute the functions of the genes and the genes are repeatedly present.
He also identified that each one has a unique pattern of the minisatellites.
Features of DNA Fingerprinting
The DNA Fingerprinting method used to identify the identity of an individual apart from his physical characteristics with the sample of DNA by identifying the unique patterns in it is known as DNA fingerprinting.
We all know that each and every cell, in our body contains DNA. Nearly 99.9 percent of the DNA between the humans is similar, where as the remaining one person makes each of us a unique individual, and this probability reduces down in case of identical twins.
Though This unique remains as a small amount there are about three million base pairs are differed between the peoples.
Minisatellites are the short sequence consisting of about 10 to 60 base pairs of the repetitive DNA which shows a greater variation from one person to the other and even in other parts of a genome. The minisatellite was first discovered in the year 1980.
DNA fingerprinting detects lots of minisatellites in the genome of an individual and thud helps us in finding the uniqueness between the two individuals or the difference.
As we all have our own fingerprinting, DNA fingerprinting is also unique with which we are born with.
DNA Fingerprinting Steps
Collection of an organic sample such as blood, buccal swap, spit, semen or a tissue.
DNA is extracted from the samples.
Restricted absorption or PCR intensification takes place.
Electrophoresis is performed
Uninterpreting outcomes are collected.
DNA Fingerprinting Process
The process followed for the DNA finger printing are discussed as follows;
Sample Collection: DNA is acquired from the body samples either in the form of liquids such as blood or semen, saliva, amniotic fluid, etc. or the tissues from particular parts.
DNA Extraction: For the process of DNA fingerprinting extracting the DNA is very much essential. High quality and the good amount of DNA is needed as it expands the conceivable outcomes for getting better results.
DNA extraction stragedy can be performed by the following strategy;
• Phenol-chloroform DNA strategy
• CTAB DNA extraction strategy
• Proteinase K DNA extraction strategy.
The immaculateness and the quantity of DNA needed could be of about 1.80 and 100ng, individually to undergo a DNA test.
DNA is filtered using the DNA sanitation in it, if it is necessary. Then the DNA is measured using the UV visible spectrophotometer and it performs one of the accompanying strategies recorded underneath.
Restriction, Absorption, Enhancement
Restriction, enhancement, absorption or DNA sequencing is performed by following the regular tragedies as
• RFLP based STR investigation
• PCR based investigation
• Real-time PCR investigation.
DNA Fingerprinting Result Analysis
After examining under a southern blotting agarose gel electrophoresis, narrow electrophoresis, ongoing intensification and the DNA sequencing the outcomes for the different DNA profiles are compared with the RT-PCR sequencing. This method is used widely in the forensic science.
Interpreting DNA Fingerprinting Results
By over viewing the DNA profiles, of different individuals, varieties, likeness and similarities between different individuals are distinguishes. Now a days all these procedures are in an automatic manner and it is computerised and we are very much thankful to the technologies.
Application of DNA Fingerprinting
Using the technique of DNA fingerprinting, the natural personality of an individual can be identified. For the identifying the ones character there is no need for alternative preferable samples of the DNA.
Gravely eradicated dead bodies can be identified.
DNA fingerprinting helps in detecting the maternal contamination of a cell.
One of the significant uses of this technique is to determine the maternal cell tainting. The amniotic fluid or the CVS test contains the maternal DNA once in a while. Contamination of the sample have the great chances of giving the false statements particularly in carrier recognition.
Using VNTRs and the STRs markers with the PCR gel electrophoresis, maternal cell tainting can be identified during the time of pregnancy hereditary testing.
The most significant use of this technique in a present-day generation is to find a crime report or a criminal check.
The sample that is taken from the crime site like salivation, blood, hair follicle or semen is collected and the DNA from the particular sample is separated and it is investigated against the suspect by utilizing the two markers which helps us to clarify.
By coordinating the band design of the DNA, criminals connected to it can be found.
DNA Fingerprinting Citations
- Age Estimation with DNA: From Forensic DNA Fingerprinting to Forensic (Epi)Genomics: A Mini-Review. Gerontology . 2018;64(4):326-332.
- DNA fingerprinting in the criminal justice system: an overview. DNA Cell Biol . 2006 Mar;25(3):181-8.
- DNA fingerprinting, DNA barcoding, and next generation sequencing technology in plants. Methods Mol Biol . 2012;862:13-22.