Segment Anything Model for Zero-shot Single Particle Tracking in Liquid Phase Transmission Electron Microscopy

Liquid phase transmission electron microscopy (LPTEM) offers an unparalleled combination of spatial and temporal resolution, making it a promising tool for single particle tracking at the nanoscale. However, the absence of a standardized framework for identifying and tracking nanoparticles in noisy LPTEM videos has impeded progress in the field to develop this technique as a single particle tracking tool. To address this, we leveraged Segment Anything Model 2 (SAM 2), released by Meta, which is a foundation model developed for segmenting videos and images. Here, we demonstrate that SAM 2 can successfully segment LPTEM videos in a zero-shot manner and without requiring fine-tuning. Building on this capability, we introduce SAM4EM, a comprehensive framework that integrates promptable video segmentation with particle tracking and statistical analysis, providing an end-to-end LPTEM analysis framework for single particle tracking. SAM4EM achieves nearly 50-fold higher accuracy in segmenting and analyzing LPTEM videos compared to state-of-the-art methods, paving the way for broader applications of LPTEM in nanoscale imaging.