Now in our 13th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

Born on this Day Revolutionary Reaction
28 December 2015

Revolutionary Reaction

Reading the DNA code (the A, C, T, G base sequence) in the early 1980s was do-able, if laborious. But pinpointing mutations – say, where there’s a C instead of a T – wasn’t easy. Kary Mullis solved this problem in 1983. His concept revolutionised a technique that became the polymerase chain reaction (PCR). Using short stretches of known DNA code that bookend the gene sequence of interest, an added enzyme (polymerase) recreates the code in between from new bases added to the mix. This duplicates the intervening sequence. The polymerase can now work on each new stretch of code as it’s created, so it's a chain reaction. In just one hour the process can generate a billion identical copies. Revealing anomalies by comparing the DNA that’s amplified becomes a rapid, straightforward procedure. PCR, for which Mullis received the Nobel Prize in 1993, went on to transform biological and forensic science.

Written by Lindsey Goff

  • Image by Erik Charlton, Flickr
  • Image copyright held by the photographer

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.