Leica Microsystems Combines Advantages of Cryo Fixation, Fluorescence Light Microscopy and Electron Microscopy in One System

Leica Microsystems launches Leica EM Cryo CLEM, a system that facilitates correlative light and electron microscopy (CLEM). In CLEM, the sample is studied under the fluorescence light microscope and the electron microscope. The system allows rapid screening of large areas and fast determination of regions of interest which can then be quickly recognized in the electron microscope. This can reduce up to 50% of the user interaction on the cryo electron microscope and helps users save time. In addition, the image data from both sources can be combined, resulting in a deeper understanding of the analyzed sample. The Leica EM Cryo CLEM system consists of a fluorescence light microscope with cryo stage, cryo objective, and a cyro transfer shuttle. It keeps cryo-fixed samples under cyro conditions during imaging in the fluorescence light microscope and during transfer. For the Leica EM Cryo CLEM system, Leica Microsystems developed the world’s first commercially available cyro CLEM objective to enable localizing of fluorescent-labeled target structures.

“Working with the Leica EM Cryo CLEM system ensures fast, safe, contamination-free sample transfer and loading from cryo sample preparation instruments to the fixed stage fluorescent light microscope Leica DM6000 FS, and maintains the controlled sample state during the cryo imaging,” explains Ruwin Pandithage, Product Manager at Leica Microsystems. “Since all components of the system originate from Leica Microsystems, they are well-matched and perform smoothly in their workflow.”

Leica Microsystems cooperation partner Dr. John Briggs of EMBL Heidelberg, Germany, says: “This will provide a huge boost to our research. It will allow us to carry out cryo fluorescence microscopy easily, reliably and with good image quality, and to efficiently recover the sample for correlative cryo electron microscopy. This will make it possible to answer a whole range of exciting research questions.”

The system’s dedicated Leica HCX PL APO 50x / 0,90 CLEM objective enables researchers to define fluorescent-labeled target structures of a size up to 100 nm. It is apochromatically corrected and has a numerical aperture of 0.9. Its low working distance of 0.28 mm ensures high resolution cryo imaging with a maximum resolution of 364 nm. A transfer shuttle keeps the sample under cryo conditions and contamination-free throughout the workflow.