Advancing Cryo-EM and Cryo-ET through Innovation in Sample Carriers: A Perspective.

Cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET) have revolutionized structural biology by enabling high-resolution imaging of biomolecules and cellular structures. However, traditional sample carriers, such as copper grids with carbon films, presented limitations, particularly in cryo-ET workflows. Issues like uneven cell distribution, beam-induced motion, and suboptimal vitrification can compromise data quality. Recent advances in sample carrier design have successfully addressed key challenges, including the development of gold-based supports, graphene coatings, and nanofluidic chips. These innovations have improved mechanical stability, enhanced thermal conductivity, and provided better control over ice layer uniformity, leading to more consistent sample preparation and higher-quality imaging. In this perspective, sample preparation advancements, novel approaches such as titanium autogrids and slot grids with continuous gold foils, and their role toward future cryo-ET applications are discussed. These new designs have the potential to simplify workflows and optimize cell growth environments. Furthermore, this perspective highlights how integrating these cutting-edge technologies with prior advancements in sample carrier design can enhance cryo-ET workflows. Combined, they enable cryo-EM imaging of thicker samples and drive progress in structural biology research.