Basic Science Imaging Platform

In-vivo imaging offers the advantages to monitor living cells, small tissue samples or even whole embryos expressing fluorescently labelled proteins of interest over a time course. This way, it is e.g. possible to study the expression pattern of proteins during the cell cycle when studying cell monolayers, or to test the response of a particular protein when a certain drug is administered. Another application would be to introduce constructs coding for a fluorescently labelled protein into embryos via electroporation in a spatio-temporal defined window and follow the fate of these cells within embryos.


Brief technical description

Cell cultures stably or transiently expressing fluorescent proteins have to be kept at nearly identical conditions as in the cell culture incubator, in particular with respect to temperature and condition of media. A typical set up would include an inverted fluorescence microscope equipped with high aperture long-distance lenses, a heating stage and CO2 supply for maintaining the buffering capacity of „open“ media. Light exposure has to be kept at a minimum to avoid phototoxic damage induced by fluorescent proteins, e.g by using controllers for coordinated illumination and camera exposition. In practice it is advisable to acquire z-stacks at each time point in order to keep cells in focus throughout capture period. After completion of recording particle tracking can be performed using dedicated software packages. Other platforms for live cell imaging are confocal microscopes, e.g. spinning disc microscopes that are fast in image recording. The before mentioned methods lend themselves also to studies of non-mammalian embryos. However, the use of a fluorescence stereo microscope offers the possibility for manipulative intervention during the observation period. (C Schöfer, Jan. 2012)