DNA FINGERPRINTINGDNA Fingerprinting is carried out in order to examine andestimate the familial relationship between two members of a family or betweentwo people. In Microbial studies it is carried out to identify the causativeorganism of the disease by identifying its genetic material that is., DNA. InForensic studies DNA Finger printing is done to solve critical crimes incriminal investigations wherein from the evidences and blood samples thecriminal is identified using this technique because enough DNA is contained ina minimal drop of blood or in root of hair. DNA fingerprinting in Forensicterms is called as DNA profiling. There isa very simple principle involved in DNA finger printing every individual hasDNA as their genetic material inherited from their parents. This DNA isinvolved in the production of particularproteins needed for life based on the codon sequence additional to this theycontain a particular DNA section which is unique to that individual.
Just likeour finger prints which is unique to each and every one that is finger print ofone individual never matches with the other, similarly these sections of DNA ofone individual doesn’t match with the others a section is inherited from theirparents and this is helpful to identify the relationships. When DNA fingerprinting is carried out with the motive of species identification not anindividual is called as DNA barcoding. There arenumerous steps involved in DNA finger printing for the aquishion of resultswith precision and accuracy. 1. DNA is present in every part of the body socollection of sample is an easy step. Mostly used sources to collect thesamples is blood , roots of hair and buccal swap is also advisable2. Generally in most of the situations the DNAavailable is minimal for instance in criminal investigations, so in order toobtain enough DNA for testing the Polymerase Chain Reaction (PCR) is carriedout where in the DNA undergoes rapid replication and results in more DNA, the main motive of this step is to improvethe amount of DNA for the test. 3.
Now theisolated and increased amount of DNA obtained is taken to the next step inwhich a few enzymes named Restriction Enzymes are involved. These Enzymes havethe ability to break the DNA at very specific and accurate sites with highdegree of accuracy. On treatment with the Restriction Enzymes it will result inthe breakage of the DNA into numerous tiny fragments of varies sizes4.
Now thesebroken fragments should undergo fine separation. This is achieved by performingan Agarose Gel Electrophoresis in which the fragmented pieces of DNA byrestriction Enzymes gets separated based on their size. DNA is chargednegatively so moves towards the positive electrode and the fragments hence getsseparated based on the size.
5. These separated fragments are taken out using anylon membrane BY the simple sieving process. Treatment with chemicals is donein order to make the DNA single stranded.
6. Next step involves the crosslinking of the DNAwhich is single stranded with the nylon with the help of heat, process is akind of similar to the Backing process or using Ultraviolet Rays.7. Decaying of the DNA strand occurs and the lightis given this results in the showing up of the probe. Finally we can find Darkspots on the film which actually is nothing but the unique DNA band of theperson the band pattern is unique and different from one person to anotherbecause we are all unique.
8. On exposure of this film to the x rayradioactive DNA sequence which even a nacked eye can detect is obtained. Abanding pattern called as DNA fingerprint is obtained.
For Example, The DNA fingerprint of a child is unique but there should be similarity between some of thebands of the child with her parents some of her bands matches with one parentwhere as some of the bands should match with the other parent. The main use ofthis technique is carried out for the identification of the biological parentsof a child whose parents claim is wrong. There are various other applicationsof DNA finger printing also. It is said that the similarity of DNA between twohumans is nearly 99.9% that 0.01% difference gives the uniqueness to everyindividual. This sequence which shows uniqueness is generally designated asMinisatellites.
But in case of identical twins it is generally not possible tocarry out this process because they are totally genetically similar. DNA FingerPrinting is a very interesting and applicable tool in crime investigations andbiological tests but there are a few oppositions to this tool. DNA fingerprinting is strictly limited only too few cases for the sake of privacy to theindividual. In the future days one important application of this technique canbe achieved.
Like how there is a barcode which expresses the uniqueness of eachproduct this technique can be used as a bar code to display the uniqueness toeach human later its span can be extended to drug designing for particularhumans a new kind of Adhar with genetic background. These small sequences with uniqueness concept can even applied in plantbreeding. It is found that the plants which undergo vegetative propagation arefound to have like DNA bands it is with similar case with self-pollination alsowhere as those undergoing crosspollination show very varied DNA bandsindicating variation. This can be used as a tool to distinguish betweendifferent types of cultivation methods. In spite of these advantages there area few disadvantages the first and foremost is that in order to increase theamount of the DNA, Polymerase Chain Reaction is done which means that duringthe synthesis of new strand the probability contamination is high and this mayresult in undesired results lading to wrong assumptions.
There are a few casesin which the errors in DNA finger printing led to the wrong person and this isconsidered as one of the strongest evidences so it needs to be highly accurate.Misusing of the technique is one problem which has to be minimized.