An Improved SEM Preparation Workflow for Plasma Membrane Imaging in HepG2 and IM-9 Cells.

Accurate visualization of the plasma membrane is essential for assessing morphological changes induced by experimental perturbations. Scanning electron microscopy (SEM) enables high-resolution imaging of cell surface architecture, but the fixation, dehydration, and drying steps critically affect membrane preservation. Here, we present an improved SEM preparation workflow for two cultured cell models with different growth phenotypes, HepG2 and IM-9, and evaluate the effects of fixation time and drying strategy on plasma membrane preservation. Among the tested conditions, a shorter glutaraldehyde fixation time (15 min) combined with stepwise ethanol-to-HMDS substitution provided the best overall preservation of membrane continuity, cell shape, and surface regularity. Morphometric analysis supported the qualitative SEM observations, and HMDS-processed samples also showed better structural stability during storage under the tested conditions. This workflow provides a simple, reproducible, and cost-effective strategy for SEM-based analysis of cell surface morphology in cultured cell models.