rapid sample processing method to observe diatoms via scanning electron microscopy

This study provides a rapid and effective processing method for scanning electron microscopy (SEM) observation of marine diatoms. The procedure consists of four stages, including concentration, dehydration, mounting, and drying, with a total processing time of less than 25 min. The incorporation of ethanol, which played important roles in both dehydration and cleaning, was optimized using three distinct ethanol concentrations (15, 50, and 100 %). In the shaking stage, we used a vortex instead of sonication to reduce cell losses. Finally, aluminum foil was chosen as the carrier on which diatoms were mounted for SEM observation. Consequently, aluminum foil allowed a large loading area, good folding performance, no interference with energy-dispersive X-ray (EDS) analysis, and good electrical conductivity. The present method helps improve the efficiency for identifying and classifying the nanoscopic structures of diatoms.