Q.Who among the following was awarded the Nobel Prize for the development of PCR technique?

The polymerase chain reaction (PCR) is a revolutionary technique that allows us to amplify a specific segment of DNA millions of times in vitro. It was invented by Kary Mullis in 1983, and this breakthrough earned him the Nobel Prize in Chemistry in 1993.

Let's quickly rule out the other names:

• Herbert Boyer co-developed recombinant DNA technology with Stanley Cohen, pioneering genetic engineering.
• Hargovind Khurana (Har Gobind Khorana) won the Nobel Prize in 1968 for deciphering the genetic code and demonstrating how nucleotides in DNA direct protein synthesis.
• Arthur Kornberg received the Nobel Prize in 1959 for discovering DNA polymerase I, the enzyme that synthesizes DNA. …

The Polymerase Chain Reaction stands as one of the most transformative inventions in molecular biology. Before PCR, obtaining sufficient quantities of a specific DNA segment for study required laborious cloning procedures in bacteria, a process that could take days or weeks. The ability to amplify DNA rapidly and precisely changed everything—from genetic research and medical diagnostics to forensic science and evolutionary studies.

Kary Mullis conceived the PCR technique in 1983 while working at Cetus Corporation in California. The elegance of his insight lay in recognizing that a simple three-step thermal cycle—denaturation of double-stranded DNA, annealing of primers to the target sequence, and extension by DNA polymerase—could be repeated over and over to produce exponential amplification. Each cycle doubles the amount of target DNA, so 30 cycles yield over a billion copies from a single starting molecule.

The technique relies on a heat-stable DNA polymerase, most famously Taq polymerase isolated from the thermophilic bacterium Thermus aquaticus, which can withstand the high temperatures needed for DNA denaturation without being destroyed. This automation-friendly feature made PCR practical for routine laboratory use.

Let's briefly consider the other scientists mentioned, all giants in molecular biology but not the inventors of PCR:

• Herbert Boyer co-founded the field of genetic engineering by developing recombinant DNA technology with Stanley Cohen in the early 1970s, enabling genes to be inserted into plasmids and cloned in bacteria. …

Method 2 -- sort by decade, then match to the discovery

Rather than recalling facts about each scientist independently, lay out the four names on a timeline of Nobel Prizes in the relevant era and match each to what it was awarded for -- the technique named in the question (PCR) then only needs to be matched to its own row: