Do you know, by chance, how scientists discovered the make-up of DNA? Was it via a microscope and if so, what type of microscope allows you to view the structure of DNA?
I believe they detected the proteins involved, they knew those long before they even knew what DNA exactly did or looked like.
Yes, I can explain how scientists discovered the structure of DNA and the role of microscopes in this breakthrough. The discovery of the structure of DNA is credited to James Watson and Francis Crick, with significant contributions from Rosalind Franklin and Maurice Wilkins.
The first step in unraveling the structure of DNA was the discovery of its composition. In 1869, a Swiss scientist named Friedrich Miescher isolated a substance from the nuclei of white blood cells, which he named "nuclein." Later on, other scientists determined that nuclein was made up of nucleic acids, now known as DNA (deoxyribonucleic acid).
To visualize the structure of DNA, scientists employed different experimental techniques, including X-ray crystallography. X-ray crystallography is a powerful method to determine the atomic and molecular structure of a crystal by analyzing the diffraction pattern produced when X-rays pass through the crystal.
Rosalind Franklin, a key figure in this discovery, used X-ray crystallography to study the structure of DNA fibers. She produced high-quality X-ray diffraction images of DNA fibers, including a critical image known as Photograph 51. This photograph provided essential clues about the helical structure of DNA.
Watson and Crick, building upon Franklin's work, used her X-ray images along with their own model building experiments to propose a double-helix structure for DNA in 1953. Their groundbreaking model explained how the DNA molecule could store and transmit genetic information.
Coming back to your question about microscopes, DNA itself is too small to be observed directly under most microscopes. Traditional light microscopes, including compound microscopes, cannot magnify objects at the molecular scale. DNA's double-helix structure was primarily revealed through X-ray crystallography, an instrumental technique rather than a microscope-based observation.
In summary, the discovery of the structure of DNA involved various experimental techniques, including X-ray crystallography, which provided critical insights into the molecule's configuration. While microscopes played a limited role in this discovery, it was primarily the advancements in X-ray crystallography and the interpretation of resultant X-ray diffraction patterns that led scientists to understand the make-up of DNA.