Polymerase chain reaction

Polymerase chain reaction is a typical example to illustrate the power of biotechnology/bio-engineering and why it is going to be the hottest field in the next few decades.

Today I was looking at the Court TV and they were showing a clip on how the polymerase chain reaction [PCR] was used to identify the criminal. This technology was invented by a Georgia Tech alumni, who went on to win the the Nobel prize for this invention. The PCR is used to amplify the amount of the DNA present in forensic samples.

For Example, let us say that there was a drop of criminal's sweat left on the crime scene. The normal genetic analysis cannot be directly performed on it, because the concentration of the DNA in the sample is very low. This low concentration can be amplified in a polymerase chain reactor.

Principle:
- Double stranded nature of the DNA. The nucleic acid in one strand attached to its complementary nucleic acid in the other strand
- polymerases are biomolecules that play vital role in DNA replication during cell division. The DNA replication is semi conservative in nature ie. the daughter cells have one of the parent strands.

Working:
- the low concentration DNA strand is heated to separate the 2 strands.
- the strands are treated with the polymerases along with the A T G C nucleic acids
- The polymerase start the replication and new DNA strands are formed.
- the DNA sample is heated again to separate the newly formed DNA
- the above 3 steps are repeated till sufficient quantity of DNA is obtained.

The DNA rich sample, can be now used for different genetic analysis.

I remember my first biotechnology seminar given by the department chair. Quoting him "50 years from now, your son will be saying that 'people were so dumb, 50 years back, that they were cutting down the rain forests to make paper'. Because in future you will have biotechnology methods to make paper out of bacterial cultures. Even though currently bio-engineering is now mainly used to address the issues in the health care, there is a lot of scope for it in the future".

I accept that Biotechnology is going to be the technology of this century, the same way as how electronics and computer science was, the previous century.