Photo 51 and DNA Structure Discovery
Rosalind Franklin captured Photo 51 in 1952 using X-ray diffraction at King’s College London. Raymond Gosling assisted with the experimental work. Maurice Wilkins showed the image to James Watson without Franklin’s permission. Watson and Francis Crick used this data combined with Chargaff’s base-pairing rules to build their DNA model in 1953.
Particle-Wave Duality in Biology
Louis de Broglie proposed matter waves in 1924. Albert Einstein and Max Planck established photon theory explaining light’s particle nature. Biologists exploit both wave and particle properties—wave behavior for diffraction-based structure determination, particle behavior for fluorescence imaging and energy transfer.
Structure-Based Drug Design
Brian Druker developed imatinib (Gleevec) for chronic myeloid leukemia based on BCR-ABL kinase structure. Pharmaceutical companies employ structural biologists determining target protein structures guiding lead compound optimization. Computational chemists use structures for virtual screening predicting binding affinities. Clinical researchers test structure-designed drugs in trials.
X-Pattern from Helical Diffraction
William Cochran, Francis Crick, and Vladimir Vand independently derived mathematical relationships between helical structures and X-shaped diffraction patterns in 1952. Watson immediately recognized Photo 51’s X-pattern as diagnostic for helical geometry after Franklin’s seminar. Structural biologists routinely identify helical proteins by characteristic X-shaped diffraction.
Fluorescent Dyes in Biological Imaging
Roger Tsien developed improved fluorescent proteins and dyes earning the 2008 Nobel Prize in Chemistry. Osamu Shimomura and Martin Chalfie discovered and applied green fluorescent protein. Cell biologists use fluorescent labels visualizing specific proteins, organelles, and dynamic processes. Microscopists employ diverse dye chemistries achieving multicolor imaging.