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प्रश्न
Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.
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उत्तर
For the PCR, two sets of primers (chemically synthesised oligonucleotides that are complementary to a region of DNA), the enzyme DNA polymerase and deoxynucleotides are added.
The PCR consists of three steps:
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Denaturation: Double helical DNA is denatured at a high temperature. DNA polymerase does not get degraded at this temperature, as the DNA polymerase used in this reaction is thermostable. It is isolated from the thermophilic bacterium Thermus aquaticus (Taq).
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Annealing: It is the step in which primers are annealed to single-stranded DNA templates. Two sets of primers (chemically synthesised small oligonucleotides that are
complementary to the regions of DNA) are used. The temperature of the reaction mixture is lowered to 50–65 °C for some seconds to allow annealing of the primers. DNA polymerase extends the primer in the 5' to 3' direction. -
Extension: Replication of DNA occurs in vitro.
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This cycle is repeated several times to generate up to one billion identical copies of DNA.
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संबंधित प्रश्न
From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?
Can you recall meiosis and indicate at what stage recombinant DNA is made?
PCR and restriction fragment length polymorphism are the methods for ______.
In addition to the Taq polymerase enzyme, which other thermostable DNA polymerases have been isolated to be used in PCR?
Illustrate the design of a bioreactor. Highlight the difference between a flask in your laboratory and a bioreactor which allows cells to grow in a continuous culture system.
Write the scientific name of the source organism of the thermostable DNA polymerase used in PCR.
Bioreactors are the containment vehicles of any biotechnology-based production process. For large scale production and for economic reasons the final success of biotechnological process depends on the efficiency of the bioreactor.
Answer the following questions w.r.t. the given paragraph:
- List the operational guidelines that must be adhered to so as to achieve optimisation of the bioreactor system. Enlist any four.
- Mention the phase of the growth we refer to in the statement "Optimisation of growth and metabolic activity of the cells".
- Is the biological product formed in the bioreactor suitable for the intended use immediate? Give reason in support of your answer.
Which enzymes act as 'molecular scissors' to cut purified DNA precisely at specific target sites?
Which enzyme is responsible for joining the desired gene to a carrier vector DNA to form recombinant DNA?
Which of the following are direct methods used for introducing recombinant DNA into host cells besides chemical transformation?
