Alink, L. M. | Search bioRxiv

bioRxiv2022

Vitrocam: A simple low cost Vitrobot camera for assessing grid quality

The most widely used sample preparation method for single particle cryo-electron microscopy (cryo-EM) today involves the application of 3-4 l of sample onto a cryo-EM grid, removing most of the liquid by blotting with filter paper, then rapidly plunging into liquid ethane to vitrify the sample. To determine if the grid has appropriate ice thicknesses and sufficient area for cryo-EM imaging, the grid must be inserted into a transmission electron microscope (TEM) and screened. This process to evaluate grid quality is costly and time consuming. Here, we present our initial attempt to image the sample preparation process in one of the most commonly used plunge freezing devices, the Vitrobot. We do this by building the Vitrocam, a Raspberry Pi high-speed camera, that captures images of grids mid-plunge. Images from the Vitrocam can be correlated to TEM atlases and show promise for providing preliminary feedback on grid quality and ice thickness.

biophysics↗

bioRxiv2021

System Environmental Metrics Collector for EM facilities

Recent developments in cryo-electron microscopy (cryoEM) have led to the routine determination of structures at near atomic resolution and greatly increased the number of biomedical researchers wanting access to high-end cryoEM instrumentation. The high costs and long wait times for gaining access encourages facilities to maximize instrument uptime for data collection. To support these goals, we developed a System Environmental Metrics Collector for facilities (SEMCf) that serves as a laboratory performance and management tool. SEMCf consists of an architecture of automated and robust sensors that track, organize and report key facility metrics. The individual sensors are connected to Raspberry Pi (RPi) single board computers installed in close proximity to the input metrics being measured. The system is controlled by a central server that may be installed on a RPi or existing microscope support PC. Tracking the system and the environment provides feedback of imminent issues, suggestions for interventions that are needed to optimize data production, and indications as to when preventative maintenance should be scheduled. The sensor components are relatively inexpensive and widely commercially available, and the open-source design and software enables straightforward implementation, customization, and optimization by any facility that would benefit from real time environmental monitoring and reporting.

biophysics↗