What is the ‘RELION simulator’?

We have turned cryo-EM data processing on its head: instead of having everyone calculate results from tutorial datasets, WE calculated the results for you! Think of a ‘choose your own adventure’ book but for cryo-EM processing.

For example, the image below shows one example of what this might look like if you visualized the tree of possible decisions in cryo-EM processing.

In 2D classification, there are several parameters to choose at your disposal:

• Particle stack – which picking run will you use?
• How many classes to ask for?
• What diameter mask to apply?

In the RELION simulator, we have precalculated thousands of outcomes and have coupled this into the RELION software package. This allows learners to input job parameters and see how it affects downstream results.