First appeared in the BayBio.org newsletter.
We’ve made some amazing technological advances in DNA-related laboratory equipment in recent years. Here at BioSurplus we have the opportunity to witness many of these first-hand: local companies Complete Genomics, Pacific Biosciences and Illumina, along with a core of Bay Area genomics-focused businesses, have been key players in the development of groundbreaking DNA sequencing technologies.
We also see this progress here in the BioSurplus showrooms where we sell pre-owned DNA sequencers, thermal cyclers, DNA synthesizers and purification systems to a growing number of clients who are ramping up their genomics-based research.
Thanks to this rapid progress, the cost of whole genome sequencing has dropped to under $10,000.00 today, from millions of dollars just a few years ago. And the potential impact of these breakthroughs on health care, and subsequently society as a whole, is enormous.
In order to understand the present and formulate an idea of what’s to come, we must look to the past for guidance. When considering the technologies that have played a pivotal role in the history of molecular biology it’s impossible to ignore x-ray crystallography and one of its premiere practitioners: Rosalind Franklin.
Rosalind Franklin and Photograph 51
Pioneering scientist, meticulous researcher and master x-ray crystallographer Rosalind Franklin made fundamental contributions to the Nobel Prize-winning identification of the double helix model of DNA.
Born in 1920 into a highly educated and socially conscious Jewish family in London, Franklin’s first exposure to science came with an early fascination with physics while at academically-rigorous Saint Paul’s Girls’ School. She went on to study at Newnham College, Cambridge, where she received a bachelor’s degree in natural sciences with a specialty in physical chemistry.
During WW II, from 1942 to 1946, Franklin conducted research using x-ray diffraction on carbons for the British Coal Utilization Research Association. Over the course of her investigations there, she published five papers on coal that have had a lasting impact on the industry; her work led to a PhD from Cambridge awarded in 1945. According to an article in Physics Today: “Her papers changed the way physical chemists view the microstructure of coals and related substances.” (Physics Today, 2003)
After a stint in Paris working with Jacques Mering at the Laboratoire Central des Services Chimiques de l’Etat, she was appointed to a post at King’s College London by Sir John Randall, Director of the Medical Research Council’s Biophysics Research Unit. While at King’s College, she was tasked to do her own research and set up a new unit dedicated to x-ray diffraction.
At this point in time x-ray crystallography had evolved from a primary focus on metallurgy and mineralogy into the area of biology. It was here that she started working on DNA structure, which led to her involvement in the double-helix model.
In one of her first experiments after arriving at King’s College, Franklin was able to identify two distinct forms in which DNA could exist: the crystalline A-form, and the fully-hydrated B-form. By controlling the humidity in her specimen chamber, she was able to hydrate A-form DNA, converting it into B-form, thus increasing its size and enabling her to take clear x-ray diffraction photographs.
The best example of these images was photograph 51, which Franklin took in 1952 using a camera she had modified and precisely focused. In a series of actions that would go down in history, Maurice Wilkins and Max Perutz shared her photo and research with James Watson and Francis Crick without her knowledge. They were subsequently able to fill in the blanks in their own research and finish developing their double-helix model of DNA, which was published in a 1953 edition of the journal Nature.
Ever-cautious, Franklin believed that their double-helix claim was on track but premature, and that more research was needed before publishing. Watson and Crick, on the other hand, believed that Franklin’s aversion to speculative thinking held her back as a scientist.
While there is no question as to Rosalind Franklin’s critical contributions to the double-helix model, the great tragedy is that she died at age 37 of ovarian cancer. And as the Nobel Prize is not awarded posthumously, she was unable to share the award with Francis Crick, James Watson and Maurice Wilkins.
We applaud the scientists that have pioneered new technology and we appreciate bringing many of these technologies to labs across the world — for a fraction of what they would cost new.