Question

Explain the contribution of Thermus aquaticus in the amplification of a gene of interest.

Answer 1

Hint: Gene amplification is an increase in the number of copies of a gene sequence. Cancer cells sometimes produce multiple copies of genes in response to signals from other cells or their environment.

Complete answer:
Thermo stable DNA polymerase enzyme is isolated from Thermus aquaticus. Polymerase chain reaction is the phenomena of making multiple copies of the DNA fragment in vitro. The double stranded DNA is denatured by using high temperature.
DNA polymerase is used to add nucleotides on the DNA strand. High temperature inactivates the DNA polymerase. Taq polymerase can withstand the high temperature used for the denaturation and separation of DNA. Each cycle of PCR includes steps for template denaturation, primer annealing and primer extension.
 The initial step denatures the target DNA by heating it to 94°C or higher for 15 seconds to 2 minutes. In the denaturation process, the two intertwined strands of DNA separate from one another, producing the necessary single-stranded DNA template for replication by the thermostable DNA polymerase.
In the next step of a cycle, the temperature is reduced to approximately 40–60°C. At this temperature, the oligonucleotide primers can form stable associations (anneal) with the denatured target DNA and serve as primers for the DNA polymerase. This step lasts approximately 15–60 seconds.
 Finally, the synthesis of new DNA begins as the reaction temperature is raised to the optimum for the DNA polymerase. For most thermo stable DNA polymerases, this temperature is in the range of 70–74°C. The extension step lasts approximately 1–2 minutes. The next cycle begins with a return to 94°C for denaturation.

Note: Each step of the cycle should be optimized for each template and primer pair combination. If the temperature during the annealing and extension steps are similar, these two steps can be combined into a single step in which both primer annealing and extension take place. After 20–40 cycles, the amplified product may be analyzed for size, quantity, sequence, etc., or used in further experimental procedures.