PCR was developed by Kary Mullis in the 1980s. It is a method in which a single copy of DNA is amplified. Using this technique which has a specific sequences ,millions of copies of DNA can be produced. In this process, many other conditions including several enzymes and primers are involved. This application of PCR extent from research to the commercial sector. Denaturation:-
The reaction mixture is heated up to 367 to 371 Kelvin for 20 to 30 minutes. It produces the softening of the double-stranded DNA by cracking the hydrogen bonds which holds the two templates together. Then the DNA molecule turns into a single-stranded one.
When the DNA strands …show more content…
For this purpose, Taq polymerase is used often.
A temperature of 343 to 347 Kelvin is usually necessary for this step to make sure complementary strands have been founded by all the single-stranded DNA templates .
Advantages of PCR technique.
1.Amplifies DNA: PCR is a great technique for DNA testing.Very tiny samples are being used for identifying the DNA of individuals. This device helps in amplifying whichever small amounts of the DNA attained.
2. Law enforcement: PCR is the best technique for crimes and legal investigations in which only a small amount of DNA are acquired.PCR duplicates the samples available through transcription.It develops the chance of recognizing the source of the DNA samples. Utilizing the technique of PCR, many offenses have been solved prosperously.
3. Better HIV test: Since PCR is more sensitive and accurate successfully, it is also quite useful in HIV testing. Rather than searching for the presence of HIV antibodies, PCR directly gazes for pro-viral DNA. At 29 days from a surmised exposure or contact ,the complexity of this test makes it 98% accurate.
Limitations of polymerase chain reaction …show more content…
If reverse PCR is done,then living organisms can be identified. Examples; diagnosis of viral infections like cytomegalovirus, hepatitis , and Influenza (flu).
PCR permits the Deoxyribonucleic acid(DNA) from a blood cell or hair follicle to be examined.Example: suspected homicides,suicides,and cases referred from the court.
3.PCR application in the identification of genetic disorder:
The Polymerase chain reaction technology has been most commonly used to amplify the gene segments which contain kenned mutations for diagnosis of inherited diseases like beta thalassemia, sickle-cell anemia,cystic fibrosis,etc.
4. PCR is especially useful for the prenatal diagnosis of inherited diseases where cells obtain from fetus by amniocentesis,etc.
5.Detection of infectious diseases; Example: tuberculosis,AIDS.
Principles of gene therapy.
The aim of gene therapy is to introduce the transgenes or gene into appropriate target cells to restore normal function, therefore, treating and preventing the disease .Similar technologies are being used in gene immunotherapy and DNA vaccines against cancer and other infectious diseases. For a long period of time, current focus with gene therapy is the need for high level of gene expression and to minimize safety issues such as immune reaction against transgene product or transfer vectors and associated cancer