In a presentation on February 22, Peter Mueller, Director of the X-Ray Diffraction Facility at the Massachusetts Institute of Technology (MIT), described to Andover students how analyzing crystal structures with x-rays could help scientists find a cure for AIDS.
Mueller has extensively studied x-ray crystallography, the process of aiming x-rays at crystals to determine their internal atomic structures. This process could be used to determine the crystal form of the protein that allows AIDS to infect human immune cells, allowing scientists to design a drug that would counteract the disease, according to Mueller.
Mueller focused his presentation on x-ray diffraction, a specific technique used in x-ray crystallography to determine the structure of unknown molecules.
He said, “Talking about crystallography is what I really like doing… it’s great fun and crystallography is beautiful.” Mueller especially enjoys “making people see how beautiful crystallography is.
Mueller began his presentation with an introductory description of crystals. He explained how crystals are classified based on their inner structures. To illustrate differences among crystals, he compared pictures of gypsum crystals found in a cave in Chihuahua, Mexico to ice crystals formed on campus.
Using a two-dimensional grid and a green laser, Mueller illustrated the process of two dimensional x-ray diffraction. He used these tools to demonstrate the interaction of wave lengths and bond lengths of two different crystals by comparing the effect of shining a green laser through the two dimensional optical grid versus the effect of shining a red laser through the same grid.
Mueller also included an anecdote about the earliest crystallographer, Johannes Kepler, who used crystallography to prove that snowflakes have hexagonal structures.
Bernhard Fasenfest ’12, Co-Head of the Andover Science and Technology Club, invited Mueller to campus to share examples of college-level scientific work with students at Andover. Mueller previously visited campus in February 2010.
Mueller displayed and explained some of the laboratory equipment he uses at MIT and spoke about potential independent projects students could pursue in the field of x-ray diffraction.
Mueller invited interested students to visit his laboratory at MIT this Saturday to provide students with a tour of a working research facility.
According to Mueller, students will see some slides of crystals, examine laboratory equipment and have the opportunity to determine the structure of aspirin.
Muller said, “Together with the trip to the lab… [Wednesday’s] talk could potentially be the starting point of a couple of independent projects involving pharmaceutically relevant structures or simply the determination of the thus far unknown structures of commonly available compounds.”
Gabbi Fisher ’13, who attended the presentation, said, “This was a great opportunity for me to get more familiar with one of the sub-fields of chemistry that I could come into when I grow up or go to college.”