X-ray diffraction |
yes |
1.5–4 Å |
from short peptides to MDa complexes and icosahedral viruses |
atoms, secondary, tertiary, and quaternary structure |
requires crystals, stringent purity |
100–500 μl of 5–30 mg ml−1
|
ordered versus disordered regions |
Single-particle EM |
no |
negative stain limited to ∼20 Å; particles in ice, ∼10 Å |
proteins >250 kD (negative stain); >400 kD (particles in ice) |
domain organization |
limited resolution |
∼100 μl of 0.1 mg ml−1
|
can image multiple conformations from one sample |
Electron diffraction |
yes |
1.5–7 Å |
15–250 kD |
atoms, secondary, tertiary, and quaternary structure |
requires 2D crystals or helical tubes |
∼100 μl of 1 mg ml−1
|
ordered versus disordered regions |
SAXS |
no |
10–20 Å |
10 kD to 0.6 MDa |
domain organization |
limited resolution |
100 μl of 5–30 mg ml−1
|
no |
NMR |
Yes |
1.5–3 Å for backbone atoms |
limited to <∼40 kDa |
atoms, secondary, tertiary, and quaternary structure |
sample molecular weight |
100–500 μl of 5–30 mg ml−1
|
atom-specific dynamics can be measured |