High-Resolution 3D Imaging of Megakaryocytes Using Focused Ion Beam-Scanning Electron Microscopy.In this chapter, we describe the study of bone marrow megakaryocytes (MKs) using a high-resolution 3D imaging approach known as focused ion beam-scanning electron microscopy (FIB-SEM).  It also describes a method combining light microscopy (LM) with FIB-SEM, a procedure called correlative light electron microscopy (CLEM), which allows the site-specific 3D imaging of MKs in tissues.
FIB-SEM
The apparatus consists of a scanning electron microscope equipped with a focused gallium ion beam, used to sequentially mill away the sample surface, and an electron beam, used to image the milled surfaces. 
scanning electron microscope
The apparatus consists of a scanning electron microscope equipped with a focused gallium ion beam, used to sequentially mill away the sample surface, and an electron beam, used to image the milled surfaces. 
focused gallium ion beam