Abstract

In this talk, I will present recent advances of our group towards connecting live-cell imaging and electron microscopy (EM) with millisecond time resolution using microfluidics. Before entering the high vacuum of an electron microscope, biological samples generally need to be fixed chemically or frozen. Due to the time required for this preparation, it is currently not possible to precisely correlate high-resolution EM images of cell structure with dynamics previously observed in the light microscope. We have been able to overcome this limitation by cryofixing cells and small model organisms with millisecond time-control directly in the light microscope through ultra-rapid cooling. This was enabled by a new liquid nitrogen-cooled microsystem, which suppresses ice crystallization through freezing at more than ~104 °C/s. Next, in order to image the frozen sample by high-resolution cryo-fluorescence microscopy, we designed a new type of light microscope that provides a high numerical aperture below the glass transition of water (-135 °C). We show that our technology can be integrated with conventional correlative light and electron microscopy workflows to open the path for understanding temporal relationships between cell activation and response in fields from neuroscience and immunology to pharmaceutical sciences.