Looking inside bacteria with cryo-IT
In cryo-electron tomography or cryo-ED, cells are frozen on the electron microscope stage using an effective coolant that prevents the formation of ice crystals and promotes the growth of vitreous (non-crystalline) ice instead. Then, a transmission electron microscope takes a series of images at different tilt angles while rotating the sample. Typically, images are taken every 1° to 3°. The 2D images are computationally combined to produce a 3D reconstruction of the sample at a resolution of a few nanometers, allowing visualization of macromolecular complexes within individual, intact hydration-frozen cells.
Cryo-ED data collection method Illustrated in the top panel are the bacteria used to generate the images. A slice through a cryo-electron tomogram Campylobacter jejuni The cell depicts different parts of its flagellum in the lower left panel. A central slice through the subtomogram average of a C. Jejuni flag motor,6 The lower right panel highlights its specific periplasmic disks—basal, intermediate, and proximal.
Cryo-ED data collection method Illustrated in the top panel are the bacteria used to generate the images. A slice through a cryo-electron tomogram Campylobacter jejuni The cell depicts different parts of its flagellum in the lower left panel. A central slice through the subtomogram average of a C. Jejuni flag motor,6 The lower right panel highlights its specific periplasmic disks—basal, intermediate, and proximal.
Close model
Overall resolution can be improved by performing a subtomogram averaging process, in which slices of a complex tomogram of interest—for example, a bacterial flagellar motor—are computationally identified, cropped, aligned, and averaged together.
The power of cryo-ED lies in its ability to produce images of macromolecular complexes in their native cellular environment, without the need to purify or denature them, and at a macromolecular resolution. In other words, its strength lies in avoiding the specific concerns expressed by Johann Wolfgang von Goethe. Fast:
When scholars study a subject, they try
If it is alive it must be killed first;
Then they have the parts, and they lose the whole.
The missing link was a living soul.
„Oddany rozwiązywacz problemów. Przyjazny hipsterom praktykant bekonu. Miłośnik kawy. Nieuleczalny introwertyk. Student.