In this episode of Tools of the Trade at CSHL, we see a nuclear magnetic resonance (NMR) machine at work. It is one of several instruments used to help identify and characterize newly synthesized molecules in John E. Moses’ chemistry lab at Cold Spring Harbor Laboratory.
The NMR helps scientists determine how atoms are connected in a molecule. Samples are lowered into the instrument which has a large magnet that generates radio waves. Each atom responds to the radio waves in a slightly different way based on what other atoms are near it. The responses are recorded in a diagram—an “NMR spectrum”—which, like a unique chemical fingerprint, allows scientists to figure out the sample’s molecular structure.
The instrument’s large tank cools the magnet with extremely cold helium. Samples are transported with a robotic set of arms and air-powered tracks before and after being lowered into the magnetic field. The robotic arms, tracks, magnet, and coolant make an interesting set of sounds as the machine operates.