Electron diffraction on frozen hydrated polysaccharides

SUMMARY Electron diffraction data were obtained on three different frozen hydrated polysaccharide specimens: pustulan single crystals, algal cell wall fragments consisting of β, 1–3 xylan, and fungal microfibrils of β,1–3 glucan. For pustulan, the diffraction pattern yields two of the crystalline lattice parameters of this polymer: a = 2·44 nm and b= 1·77nm. The results with β,1–3 xylan and β,1–3 glucan are identical to already known X‐ray data, but also provide information on the molecular orientation at the micrometre level. In all three cases the hydrated electron diffraction diagrams are compared with the corresponding diagrams of the dried specimen.