(Confocal) Light Microscopy
We have a Zeiss Axiovert (a) and a Zeiss Axioplan (b) both equipped with fluorescence, phase contrast and several DIC objectives.
The Zeiss Axiovert is additionally equipped with a fast scanning confocal microscope (VTinfinity) with a maximum frequency of 360 frames per seconds, depending on the camera.
The available detection cameras are: Roper CoolSnap HQ, Roper Cascade1K, and the Hamamatsu C9100.
The movie here shows labeld fd viruses (L=880 nm, D=6.6 nm) dispersed in a background nematic phase of unlabeled fd viruses.
( P. Lettinga )
Transmission electron Microscope (TEM)
Our laboratory is also equipped with a Zeiss Libra 120 Transmission Electron Microscope (TEM), operating at 120 keV. It uses a LaB6 cathode, has an in-column energy filter, can be operated in STEM mode and is equipped with a Gatan US1000 (2k x 2k) CCD camera. The microscope is used for routine characterization of silica and gibbsite-based model systems, for example, and in the development of novel colloid systems. Working in cooperation, other groups also make use of the microscope, e.g. in the study of protein aggregation.
Image-time Correlation Spectroscopy: Dynamical Events of Images
Image-time correlation spectroscopy is used to characterize the dynamics of structures of a size that permits to record spatially resolved microscopy images. The time-resolution ranges from about 0.1 seconds to many hours. Examples where we are using the technique are, the dynamics of (chiral-) nematic texture from depolarized images, the dynamics of an electric field induced dynamical state where nematic domains melt and form, and the dynamics of colloidal particles that form strings under the influence of an electric field.
The idea behind this technique is as follows. A time series of images is recorded with (for example) a CCD camera. An image-time correlation function is constructed from these images, which is defined as, where the intensity of a single pixel at time t, and where the brackets denote averaging over all pixels of the CCD camera.