A cryo-electron microscope produces a beam of electrons that passes through a frozen sample deposited on a metal mesh. The beam of electrons projects an image of the sample onto a CCD detector. High-resolution three-dimensional models of the biological sample are then generated through sophisticated image processing.
Is cryo-EM the right technique for your project?
- Yes, if your sample can’t be crystallized. Many biomolecules are difficult to crystallize or won’t crystallize at all. And in some cases, the process of crystallization may introduce artefacts that alter the conformation of the biomolecule. Cryo-EM doesn’t require crystals.
- Yes, if it is difficult or impossible to produce highly concentrated samples. X-ray crystallography and NMR spectroscopy require large sample solution at high-concentration (hundreds of microliters at > 100 µM). Cryo-EM can be conducted with 3 μl sample solution at a concentration of 0.05 – 5 μM.
Cryo-EM instrumentation available on campus
The cryo-EM Facility at ISU is home to a Glacios 200 kV microscope equipped with X-FEG, Cryo-autoloader system, Gatan K3 detector, EPU for grid screening and serial EM for screening and data collection.