New controlled environment vitrification system for cryo-transmission electron microscopy: design and application to surfactant solutions

A newly designed controlled environment vitrification system for cryo-trans mission electron microscopy of vitrified samples (cryo TEM) is presented. I t significantly reduces the lag-time from blotting to Vitrification by mean s of an optimized blotting procedure. Furthermore, a modified transfer syst em allows rapid transfer of the vitrified sample into the microscope and re duces the equilibration time. The practicable throughput of samples is ther eby markedly increased. This new equipment is used to determine the overall size of individual polymer-like mixed lecithin-bile salt micelles, which v ery critically depends on the composition of the sample. The quantitative a greement with the results from independent light scattering experiments an the same sample supports the validity and performance of the presented samp le preparation and handling procedures. In addition, these experiments demo nstrate that cryo TEM experiments not only provide direct structural inform ation, but furthermore permit a quantitative determination of micellar prop erties.