Rm. Abeysekera et al., IMPROVED VISUALIZATION OF FOLDED COLLAGEN ALPHA-CHAINS BY ULTRA-RAPIDFREEZING, International journal of biological macromolecules, 15(5), 1993, pp. 313-315
Transmission electron microscopy techniques are commonly employed to e
xamine the folded polymer structure of collagen polypeptides. These te
chniques include deposition of a sample by spraying, slow freeze-fixat
ion, air drying and vacuum drying the specimen at room temperature, an
d using additives such as glycerol in the collagen preparation. Here w
e report preliminary observations of type I collagen alpha-chains, fol
ded in water, at a concentration of 35 mug ml-1 and 10 mug ml-1, visua
lized by an ultra-rapid freeze-fixation technique designed to minimize
structural deformation caused by spraying, additives and poor freeze-
fixation. The technique also allows the use of submicrolitre sample vo
lumes of known concentrations with negligible loss and shearing, while
at the same time providing excellent contrast to the collagen polymer
for electron microscopy. This technique can be employed to study the
structure of a wide range of macromolecules (proteins and carbohydrate
s).