As a versatile structure determination technology, cryo-EM is an integrated part of the HARC Center. In the past funding cycle, the Cryo-EM Core has engaged in technology development of single-particle cryo-EM, and has made major contributions to the recent technological breakthroughs in single particle cryo-EM that has led to a resolution revolution. Briefly, we developed one of the very first programs to correct beam-induced image motion, developed a novel approach of using conformation-specific Fabs to facilitate single particle cryo-EM studies, determined the first atomic structure of an integral membrane protein that changed the perspective of the entire structural biology community, determined atomic structures of integral membrane proteins in lipid nanodiscs and developed a novel saposin-based lipid nanoparticle system for single particle cryo-EM studies of small integral membrane proteins. In this renewal, we will both focus on methodology development as well as application of state-of-the-art single particle cryo-EM technology to solve critical HIV structural biology questions.