Correlative Light Electron Microscopy (CLEM) is a technique that uses both light and electron microscopy to examine the specimen. CLEM at the BIF allows users to examine ultrathin sections on the TEM grid using the FEI iCorr fluorescence imaging system and the FEI Tecnai TEM. With the iCorr system, Green Fluorescence Protein (GFP) expressed in the sample or fluorescently (Alexa 488, FITC) immunolabelled molecules or structures can be viewed and used to find the region of interest on the section. The mode can then be switched to TEM mode to zoom in and acquire high-resolution images.
Equipment and Software:
iCorr system integrated with FEI Tecnai G2 Twin TEM
Sample Preparation:
Samples need to be fixed and embedded in acrylic resins, such as LR White and HM20, for two reasons
(1) to retain the fluorescence properties of the GFP expressed in the sample and
(2) to retain the epitopes for antibody binding to perform the immunolabelling on the sections.
Ultrathin sections will be required.
The iCorr system was installed in Feb 2018.