Cryo-electron tomography (cryo-ET) enables high-resolution visualization of cellular structures at the nanometer scale. Conventional sample preparation for cryo-ET often involves culturing cells directly on electron microscopy (EM) grids or blotting after deposition to achieve vitrification. Here, we present a novel microfluidic technology that enables simple and reliable cryo-ET sample preparation. We fabricated a thin, parylene-based microfluidic chip that can preserve mechanical integrity while supporting rapid vitrification. The device traps cells at defined locations via a simple loading step, with the option for subsequent on-chip culture. The entire thin-film chip can be vitrified by plunge-freezing, after which cell lamellae are prepared by cryo-focused ion beam (cryo-FIB) milling for cryo-ET imaging. Using this approach, we demonstrated cryo-ET imaging of ultrastructure in both suspended and adherent cells within the device. This platform offers a versatile method for investigating cellular ultrastructure and can be integrated with optical or electrical stimulation modules to enable time-resolved studies of transient cellular responses.
Tirfe et al. (Sun,) studied this question.