Prelude ======= Intended audience ----------------- The recent rapid development of single-particle electron cryo-microscopy (cryo-EM) allows structures to be solved by this method at almost atomic resolutions. Providing a basic introduction to model building, this tutorial shows the initial workflow aimed at obtaining high-quality atomic models from cryo-EM maps by using the *Scipion* software framework. We'd like to hear from you -------------------------- We have tested and verified the different steps described in this demo to the best of our knowledge, but since our programs are in continuous development you may find inaccuracies and errors in the text. Please let us know about any errors, as well as your suggestions for future editions, by writing to scipion@cnb.csic.es. Requirements ------------ This tutorial requires, in addition to *Scipion*, the `CCP4 suite `_ including *Refmac*, and *Coot*, and the `PHENIX suite `_.