SPHIRE-crYOLO: A fast and accurate fully automated particle picker for cryo-EM

Abstract

Selecting particles from digital micrographs is an essential step in single particle electron cryomicroscopy (cryo-EM). Since manual selection is a tedious and time-consuming process, many automatic particle pickers have been developed. However, they have problems especially with non-ideal datasets. Here, we present a novel automated particle picking software called crYOLO, which is based on the deep learning object detection system \"You Only Look Once\" (YOLO). After training the network with 500 - 2,500 particles per dataset, it automatically selects the particles with high accuracy and precision reaching a speed of up to six micrographs per second. Importantly, we show that crYOLO can be trained to select previously unseen datasets paving the way for completely automated \"on-the-fly\" cryo-EM data pre-processing during data acquisition. CrYOLO is available as standalone program under http://sphire.mpg.de/ and will be part of the image processing workflow in SPHIRE.