PT - JOURNAL ARTICLE AU - Radostin Danev AU - Dimitry Tegunov AU - Wolfgang Baumeister TI - Using the Volta phase plate with defocus for cryo-EM single particle analysis AID - 10.1101/085530 DP - 2016 Jan 01 TA - bioRxiv PG - 085530 4099 - http://biorxiv.org/content/early/2016/11/03/085530.short 4100 - http://biorxiv.org/content/early/2016/11/03/085530.full AB - Previously, we reported an in-focus data acquisition method for cryo-EM single particle analysis with the Volta phase plate (VPP) (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also enables 3D reconstructions with resolutions in the 2 Å range, demonstrating that, in practice, there are no resolution limitations imposed by the VPP.