Procurement of a cryo-confocal fluorescence microscope

The IBMM wishes to procure a brand-new cryo-kFM, which is to be integrated into a cryo-CLEM workflow for cellular cryo-ET and in situ structural biology. The cryo-kFM is to be equipped with at least four fluorescence channels (lasers) and feature a highly sensitive, high-resolution detector system for confocal microscopy. The microscope system should also allow switching between confocal and wide-field fluorescence microscopy by being fitted with the appropriate light sources, filters and camera. Furthermore, it should be equipped with at least one cryo-compatible air objective with the highest possible numerical aperture and a magnification of at least 50x. Furthermore, the cryo-kFM should feature a cryo-stage that allows samples (cryo-EM grids with vitrified cells) to be loaded, imaged and unloaded at temperatures below –150°C, without the samples ever being exposed to higher temperatures and without them being significantly contaminated by condensing moisture.

The cryo-stage must be compatible with standard cryo-EM grids and so-called AutoGrids for the subsequent cryo-CLEM steps. The motorised cryo-stage should be integrated into the user interface of the software used to operate the cryo-kFM. This user interface should be as simple and efficient to use as possible; the entire microscope system should comprise a complete, ready-to-use hardware and software package. Of particular importance are high imaging quality, robustness when retrieving the imaged samples without any loss of quality for the subsequent cryo-CLEM steps (cryo-FIB milling and cryo-ET), and user-friendliness.