Integration of an Event-driven Timepix3 Hybrid Pixel Detector into a Cryo-EM Workflow

The development of direct electron detectors has played a key role in low-dose electron microscopy imaging applications. Monolithic active-pixel sensor detectors are currently widely applied for cryogenic electron microscopy (cryo-EM); however, they have best performance at 300 kV, have relatively low read-out speed and only work in imaging mode. Hybrid pixel detectors can operate at any energy, have a higher detective quantum efficiency (DQE) at lower voltage, have unprecedented high time resolution, and can operate in both imaging and diffraction modes. This could make them well-suited for novel low-dose life-science applications, such as cryo-ptychography, iDPC, and liquid cell imaging. Timepix3 is not frame-based, but truly event-based, and can record individual hits with 1.56 ns time resolution. Here, we present the integration of such a detector into a cryo-EM workflow and demonstrate that it can be used for automated data collection on biological specimens. The performance of the detector in terms of modulation transfer function and DQE has been investigated at 200 kV and we studied the effect of deterministic blur. We describe a single-particle analysis structure of 3 Å resolution and compare it with Falcon3 data collected using the same microscope. These studies could pave the way towards more dose-efficient single-particle techniques.