Our impact

We are dedicated to advancing the field of cryo-EM structure determination. To help others in their structure determination efforts we make all our algorithm developments available through our open-source software package RELION. We are worried about a trend towards closed-source programs and other forms of protection related to commercialisation in the field, which ultimately slow down scientific progress. We believe that the fruits of our public funding (from the UK Medical Research Council) should be open and free to use for anyone. Therefore, RELION is distributed under the GPU general public license (v2). Besides our open software contributions, we also provide access to video and slide materials of our locally organised EM-course. The journal Nature recognised our impact by listing Sjors as one of the ten people who mattered in 2014, and Sjors was elected as a Fellow of the Royal Society in 2021, a Fellow of the Academy of Medical Sciences in 2022, and a Foreign Member of the Royal Netherlands Academy of Arts and Sciences (KNAW) in 2022. You can follow (citations to) Sjors' papers through his Google Scholar profile.


The empirical Bayesian approach to single-particle analysis that we developed has been implemented in an open-source program called RELION (for REgularised LIkelihood OptimisatioN). RELION may be downloaded for free; see the RELION Wiki for instructions.

RELION played a crucial role in our demonstration that cryo-EM structures to near-atomic resolution may be obtained from only several tens of thousands of particles, and has become one of the most popular software packages to determine cryo-EM structures worldwide. Development of helical reconstruction in RELION also pioneered atomic structure determination of amyloid filaments. We even showed that these methods can be applied on filaments that were purified from the brains of individuals with different neurodegenerative diseases. Many other groups now also use RELION for amyloid structure determination. In our own lab, RELION continues to produce great structures: see the structures tab for an overview.

The introduction of the first prototypes of the new direct-electron detection cameras in 2012, coincided with the introduction of RELION. Therefore, it is difficult to disentangle the effects of the two developments on the so-called 'resolution revolution' in the cryo-EM field. An interesting, pre-revolution result came from the group of Joachim Frank, the original developer of the SPIDER software. Reprocessing of old, film data on a ribosomal pre-termination complex in his group led to a resolution improvement from 18 Angstroms in SPIDER to 9.7 Angstroms in RELION. The almost doubling of resolution compared to previously existing software illustrates that, besides the major contribution of direct-electron detectors, RELION's role in the revolution was also substantial.

LMB EM-course

With the recent advances in cryo-EM structure determination, we find that an ever increasing number of people want to learn about it. To aid those new to the field, together with Lori Passmore and Paula daFonseca, we organized a course at LMB that covers the theoretical basis of modern cryo-EM structure determination. The slides and professionally edited videos of all ten lectures in this course may be downloaded for free from here. They are also available on the MRC-LMB YouTube channel


RELION-3.1 released

Download from here

RELION provides a Bayesian approach to single-particle refinement. As such, it may be used to obtain reference-free 2D class averages, unsupervised 3D classifications, or state-of-the-art high-resolution refinements, all with minimal user intervention. The 3.0 release includes Bayesian polishing and CTF refinement to improve the resolution of many structures.