Cryoelectron microscopy of liposomes.

A thin aqueous film of suspended lipid vesicles?micelles is the object of choice for vitrification and subsequent study by cryoelectron microscopy. Just prior to vitrification, a thin film (compare with a soap film) is vulnerable to heat and mass exchange. Preparation of thin films in a temperature- and humidity-controlled environment is essential to prevent osmotic and temperature-induced alterations of the lipid structure, as will be explained in this chapter. Further automation of the preparative procedure by automatic blotting and PC control over the timing of critical steps (including vitrification) may further assist in the reproducible throughput of high-quality specimens. By cryotomography, taking a tilt series under low-dose conditions, a three-dimensional reconstruction of the specimen can be analyzed.