DNA Fingerprinting Definition

DNA is an acronym for deoxyribonucleic acid, a type of nucleic acid found inside every cell in your body. It is a series of chemical molecules that combine to generate irreversible blueprints for life.

These are known as bases, and there are four of them. They combine to generate what are known as base pairs. Your DNA contains approximately 3 billion of these pairs. The way they are connected instructs your cells on how to replicate themselves.

A genome is the whole collection of your compounds. Over 99.9 percent of everyone’s genome is identical (100 percent if you are identical twins). However, the little amount that is not is what distinguishes you physically and emotionally from another person.

DNA fingerprinting is a technique that separates DNA strands and reveals the unique components of your genome. The results appear as a striped pattern that can be compared to other samples.

Principle of DNA Fingerprinting

The human genome is made up of an enormous number of tiny noncoding sequences, all of which are inheritable and appear repeatedly in the population. They can be extracted from the bulk DNA by undergoing density gradient centrifugation, and as a result, they are referred to as satellite DNA (satellite DNA). According to their length, base composition, and tandemly repeating units, they can be classified as microsatellites or microsatellites and microsatellites and microsatellites respectively. 

Satellite DNAs exhibit polymorphism, and it is this polymorphism that serves as the foundation for DNA fingerprinting. Variable number tandem repeats (VNTRs) and short tandem repeats (STRs) are two types of repeat regions that can be distinguished based on the size of the repeat. Individuals inherit these repeats from their parents, and these repeats serve as genetic identifiers for each individual. As a result, each individual has a unique mix of VNTRs, which is the fundamental idea behind the DNA fingerprinting technique.

Application of DNA Fingerprinting

• The innate personality of a person can be discovered through the use of DNA fingerprinting techniques. There is no more suitable alternative to DNA fingerprinting when it comes to approving a person’s personality.
• It is possible to distinguish between gravely injured dead bodies.
• It is used to detect the presence of maternal cell contamination.
• One of the most major drawbacks of pre-birth determination is the tainting of maternal cells. Occasionally, the amniotic fluids or CVS test will contain the maternal DNA or maternal tissue, depending on the circumstances. Contamination increases the possibility of false-positive results, particularly due to carrier recognition, by increasing the likelihood of contamination. Maternal cell tainting can be detected during pregnancy hereditary testing by using VNTRs and STRs markers in conjunction with PCR-gel electrophoresis.
• One of the most significant applications of the current method is in the investigation of crime scenes and the conduct of criminal background checks. The evidence is gathered from the murder scene, and it could be salivation, blood, hair follicles, or male reproductive organs. DNA is extracted and compared to the suspect’s DNA using the two indicators that we previously clarified in our investigation. It is possible to create a database of criminals associated with wrongdoing by coordinating DNA band designs.

DNA Fingerprinting Steps

• Collection of organic material such as blood, spit, buccal swab, sperm, or solid tissue is permitted.
• DNA extraction is performed.
• Restriction absorption or PCR intensification.
• Agarose gel electrophoresis, slim electrophoresis or DNA sequencing.
• Putting the results into context.

The Process of DNA Fingerprinting

Sample collection, DNA extraction, absorption or intensification and inquiry results are important breakthroughs.

Stage 1: Sample Collection 

A person’s DNA can be obtained from almost any biological sample or liquid. Buccal smears, salivation, blood, amniotic fluid, chorionic villi, skin, hair, bodily fluid, and various tissues are all examples of samples that are frequently used in clinical trials.

Stage 2: DNA Extraction 

First and foremost, we must obtain DNA. For the sake of carrying out any genetic applications, DNA extraction is one of the most significant technological advancements. A high level of DNA quality and quantity increases the likelihood of obtaining better outcomes.

You can utilize DNA extraction strategies enrolled beneath, 

1. The Phenol-chloroform DNA extraction process
2. The CTAB DNA extraction process 
3. The Proteinase K DNA extraction process

Using a ready-to-use DNA extraction unit for DNA fingerprinting, on the other hand, is something we strongly recommend.The immaculateness and amount of DNA required to carry out the DNA test should be 1.80 and 100ng, respectively. In the event that it is necessary, filter the DNA through the DNA sanitisation unit.From that point on, the DNA will be measured with the help of a UV-Visible spectrophotometer. In addition, implement one of the tactics listed below to supplement your current efforts.

Stage 3: DNA Sequencing 

Three strategies are Generally utilized: 

1. RFLP based STR investigation 
2. PCR based investigation 
3. Real-time PCR investigation

Stage 4: Analysis of Results 

As we discovered, different DNA profiling techniques such as southern blotting, agarose gel electrophoresis, narrow electrophoresis, ongoing intensification, and DNA sequencing can be used to obtain results for different DNA profiling, with rt-PCR and DNA sequencing being the most commonly used in forensic science.

Stage 5: Interpreting Results 

By comparing DNA profiles of different individuals, it is possible to identify genetic variations and similarities between people. The fact that the entire procedure is now practically automatic is remarkable. We don’t have to do anything because the computer provides us with conclusive results.

Conclusion

As a method of extracting and identifying variable elements within the DNA base-pair sequence, DNA fingerprinting is also known as DNA typing, DNA profiling, genetic fingerprinting, genotyping, or identity testing (deoxyribonucleic acid). In 1984, British geneticist Alec Jeffreys devised the approach after noticing that certain highly variable DNA sequences (known as minisatellites) are repeated within genes but do not contribute to their functions. He discovered that each person has a distinct pattern of microsatellites (only exceptions is being multiple individuals from a single zygote, such as the identical twins).