|
Reverse
transcription is another method of acquiring a gene. It is
called reverse transcription as it is directly opposite to
the process of transcription.
Remember we have
discussed that DNA is protected from mutation by the nuclear
membrane. The genetic code is first transcribed onto a mRNA.
The mRNA molecule is responsible for the synthesizing of
proteins in the cytoplasm.
With advancement
of technology, scientists are able to isolate individual
mRNA molecules in the cytoplasm. Then they will identify
them and select the mRNA molecule that corresponds to the
gene they need. The mRNA is separated in a solution. DNA nucleotides, DNA ligases, and DNA polymerase is then added
to it. The nucleotides will form hydrogen bonds with the
mRNA and they are joined together by the ligases. A DNA
segment is thus formed. The gene can be duplicated many
times by Polymerase Chain Reaction (PCR).
Reverse
transcription is much faster compared to cutting DNA by
restriction enzymes. This is because it is very troublesome
to choose the right restriction enzyme and to painfully
identify the many segments of genes cut by the enzyme. On
the other hand, little identification process is needed in
reverse transcription.
Relating Topics
-
Transcription
-
PCR
| 
