Time-resolved cryo-EM using Spotiton

We present an approach for preparing cryo-electron microscopy (cryo-EM) grids to study short-lived molecular states. Using piezoelectric dispensing, two independent streams of similar to 50-pl droplets of sample are deposited within 10 ms of each other onto the surface of a nanowire EM grid, and the mixing reaction stops when the grid is vitrified in liquid ethane similar to 100 ms later. We demonstrate this approach for four biological systems where short-lived states are of high interest.