Rosalind Franklin 1920 - 1958
Rosalind Franklin was an English chemist who is known for her X-ray crystallography work. Her famous photograph 51 helped Watson and Crick understand the molecular structure of DNA (Deoxyribonucleic acid). I used to work in the building that housed their original model of DNA structure. The story of how they saw the photo, published their studies in the same issue of Nature and how Rosalind Franklin missed out on a Nobel prize is certainly an interesting one.
She also worked on the structure of coal and graphite which was important in the production of gas masks and on understanding the structure of viruses including the tobacco mosaic virus which can be used to genetically alter plants.
This week I have included a range of practical activities based on DNA including one where you will need your parents to extract DNA from strawberries. Having extracted DNA myself from different samples I was amazed to see that you can do it at home and still have that same final experience of spooling out DNA from your container at the end. I have also enjoyed making DNA bracelets and I am sure I would only end up with short pieces of yummy gummy DNA as I would eat the rest!
There is lots of interesting information about the history of DNA and its uses on the timeline. You can click on images to find more details. When I started my research I used the Sanger method of sequencing which included pouring very thin sequencing gels, sequencing the DNA by hand and loading them on the gels. The pictures you see are X-rays of the radioactively labelled bases. You then read the patterns as though going down a ladder and sometimes it would be hard to see which letter came next. Later on there were sequencing machines which would do all the hard work for you and produce graphs with the sequence in 4 different colours for the 4 different nucleotides (GATC).
It is just under 70 years since Rosalind Franklin made her important discovery about DNA structure. I wonder what the next 70 years will bring?