Question

Rearrange the following in the correct sequence to accomplish an important biotechnological reaction:
(a) In vitro synthesis of copies of DNA of interest
(b) Chemically synthesized oligonucleotides
(c) Enzyme DNA-polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymerase (from Thermus aquaticus)
(i) Denaturation of ds-DNA

Answer 1

The given reaction is that of Polymerase Chain Reaction.

Explanation:

• The correct order is stated below sequentially:

1. The genomic DNA template(e) is used to amplify specific DNA sequence of interest from it.
2. When the double stranded genomic DNA is subjected to high temperature its undergoes denaturation (i).
3. Primers(g) sequence anneal to the complementary region of the DNA(d).
4. The enzyme thermostable DNA polymerase (c,h) extends the primer sequence by adding the oligonucleotides (b,f).
5. This in-vitro polymerisation reaction results in the generation of  multiple copies of the DNA of interest (a).

• Polymerase Chain Reaction is a process in which multiple copies of a particular DNA sequence can be obtained in-vitro by the use of a thermostable DNA polymerase, primers, oligonucleotides and a template DNA carrying the sequence of interest.