Question

1. Describe the process of PCR. Why is it utilized by those in the scientific community?
2. What role does a thermocycler play in the PCR process?
3. How is Taq Polymerase different from a normal DNA Polymerase? Why is this difference beneficial?
4. What role do primers play in the PCR process?
5. Why are PCR products separated by gel electrophoresis? On what basis are the PCR products separated?

Answer 1

PCR is very useful procedure in molecular biology called the polymerase chain reaction . It is a technique used to amplify a segment of DNA of interest or produce lots and lots of copies . There are three steps in the PCR process they are  

* Denaturation

*Annealing

*Extention

Denaturation process is as in DNA replication , the two strands in the DNA double helix need to be separated . The separation happens by raising the temperature of the mixture , causing the hydrogen bonds between the complimentary DNA strands to break.

Annealing process is primers bind to target DNA sequences and initiate polymerisation . This can only occur once the temperature of the solution has been lowered . One primer binds to each strands .

Extension process is new strands of DNA are made using the original strands as templates . A DNA polymerase enzyme joins free DNA nucleotides together .

Polymerase chain reaction (PCR) is often considered as one of the most important scientific advances in the field of molecular biology . With this revolutionary yet expensive biochemical technology , it is possible to generate millions of DNA copies from a single strand of DNA . PCR also used in medical and forensic applications . I can also used in the identification and detection of infectious diseases and for a wide variety of research purpose in the field of molecular genetics.

The thermocycler is a laboratory apparatus most commonly used to amplify segments of DNA via the polymerase chain reaction . Thermal cyclers also regulate the temperature during cyclical programs and lid security , heat block reliability , and overall design specifications

DNA polymerase is an essential component for PCR due to its key role in synthesizing new DNA strands . consequently ,understanding the characterstics of this enzyme and the subsequent development of advanced DNA polymerases is critical for adapting the power of PCR for a wide range of biological applications . since the use of taq DNA polymerase in the early protocols ,significant improvements have been made specifically in the specifcity enzymes. In amplifying long templates , Taq DNA polymerase may need to be supplied in higher amounts or replenished for prolonged incubation periods . Thus DNA polymerase isolated from hyperthermophilic organisms have become instrumental in overcoming these challenges , due to their thermostability.

A primer is a short strand of RNA or DNA that serves as a starting point for DNA synthesis . The role of the primer is indeed to allow the polymerase to start , because it can not just stat by itself on a single stranded piece of DNA.

Gel eiectrophoresis is a technique used to separate DNA fragments according to their size , and charge . Electrophorosis involves running a current through a gel containing the molecules of interest . Based on their size and charge , the molecules will travel through the gel in different directions or at different speeds, allowing them to be separated from one another.