Platinum replicas of broken-open osteoclasts imaged by transmission electron microscopy

• Published in: Journal of oral biosciences Vol. 63; no. 4; pp. 307 - 318
• Main Author: Akisaka, Toshitaka
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2021
• Subjects: Actin cytoskeleton; Adherent cultured cells; Cytoskeleton - metabolism; Detergent extraction; Microscopy, Electron; Microscopy, Electron, Transmission; Osteoclasts - metabolism; Physically breaking open; Platinum - metabolism; Platinum replica electron microscopy; Physically breaking open; Adherent cultured cells; platinum; three-dimensional; carbon; electron microscopy; transmission electron microscopy; Detergent extraction; Actin cytoskeleton; osteoclast; Platinum replica electron microscopy; endoplasmic reticulum; lamellipodium
• ISSN: 1349-0079; 1880-3865
• DOI: 10.1016/j.job.2021.09.006

Preserving the cellular structure at the highest possible resolution is a prerequisite for morphological studies to deepen our understanding of cellular functions. A revival of interest in rapid-freezing methods combined with breaking-open techniques has taken place with the development of effective and informative approaches in platinum replica electron microscopy, thus providing new approaches to address unresolved issues in cell biology. The images produced with platinum replicas revealed 3D structures of the cell interior: (1) cell membranes associated with highly organized cytoskeletons, including podosomes or geodomes, (2) heterogeneous clathrin assemblies and membrane skeletons on the inner side of the membrane, and (3) organization of the cytoskeleton after detergent extraction. In this review, I will focus on the platinum replica method after brokenopen cells have been broken open with mechanical shearing or detergent extraction. Often forgotten nowadays is the use of platinum replicas with stereomicroscopic observations for transmission electron microscopy study; these “old-fashioned” imaging techniques, combined with the breaking-open technique represent a highly informative approach to deepen our understanding of the organization of the cell interior. These are still being pursued to answer outstanding biological questions.