Genetic fingerprinting is carried out using various methods, which are as follows:
- Restriction Fragment Length Polymorphism: This process is also called as the Southern blot test. This method makes use of proteins called restriction enzymes to cut the DNA strands. The pieces of DNA are then separated using gel electrophoresis, a process that separated DNA strands based on their size and the corresponding negative charge that varies with the size. The DNA thus separated is transferred on to a nitrocellulose paper, which is then placed in the incubator so that DNA is permanently attached to the paper. This DNA is further analyzed using a radioactive probe. The variable number tandem repeats which are nothing but a short nucleotide sequence in the DNA, are unique for every person and hence this test helps to generate a DNA fingerprint of a particular person. A major disadvantage of this method is that it is very slow and requires a larger DNA sample.
- Polymerase Chain Reaction Polymerase Chain reaction is a very popular DNA fingerprinting method which includes amplification of specific portions of DNA using high temperature and thermostable polymerase enzyme with labeled DNA primers. Commercial PCR kits have made the process a very simple and easy method of DNA fingerprinting.
- Amplified Fragment Length Polymorphism This ia another popular method of genetic fingerprinting which scores over Restriction Fragment Length Polymorphism since it is far more time-effective. It makes use of polymerase chain reaction to amplify the DNA and focuses on the variable number tandem repeat to distinguish various DNA samples. The lower cost and the convenient operation and set up of this method makes it a popular method of genetic fingerprinting
