Abstract
The use of fluorescent protein for live imaging is an effective method of determining the localization of various proteins and organelles in cells or in tissues. Fluorescence labeling of organelles is useful for the study and analysis of the ultrastructure of plant organelles. To obtain electron micrographs of fluorescently labeled organelles and cells, we developed a correlative light and electron microscopy and successfully visualized the green fluorescent protein (GFP)-labeled organelles in resin by using a combination of confocal laser scanning microscopy (LSM) and field-emission scanning electron microscopy (FE-SEM). Organs of an Arabidopsis thaliana plant expressing GFP-labeled organelles were fixed and then embedded in acrylic resin. The block was cut by the ultramicrotome, and 1 µm-thick sections were placed on a glass slide. Then the GFP fluorescence images were acquired by performing LSM. Subsequently, these sections were stained with heavy metals, and electron microscope images of stained sections were acquired by FE-SEM utilizing a high-sensitivity reflection electron detector. Finally, the ultrastructure of the GFP-labeled organelles was analyzed by merging the fluorescence image and the electron micrograph.
