Modular microfluidics enables kinetic insight from time-resolved cryo-EM

One central goal of biochemical research is the structural and kinetic characterization of the chemical processes underlying integrated cellular functions. Usually such knowledge is inferred from a combination of methods, including atomic structures of trapped reaction intermediates, lower resolution structural information about transient states, kinetic activity assays and molecular dynamic simulations. Acquiring structural and kinetic data is challenging, as evidenced by the relatively limited number of biochemically-relevant processes that have been studied at atomic spatial resolution and on the relevant timescale.
The Peter group (IBC) in collaboration with ScopeM at ETH, CNU in Korea and CRICK in UK developed a novel time-resolved sample preparation method for cryo-electron microscopy (trEM) using a modular microfluidic device, featuring a 3D-mixing unit and variable delay lines that enables automated, fast, and blot-free sample vitrification. This approach not only preserves high-resolution structural detail but also substantially improves sample integrity and protein distribution across the vitreous ice. The method was validated by visualizing reaction intermediates of early RecA filament growth across three orders of magnitude on sub-second timescales. This method is versatile, reproducible, and readily adaptable to a broad spectrum of fundamental questions in biology.
 

Link to the paper in external page "Nature Communications".