# Hints for Tutors: Raspberry Electrophoresis Tutorial

## Learning objectives (physics)

After the tutorial, students should be able to

* explain
  * the basics of electrophoresis to a 2nd year physics student
  * the term hydrodynamic radius
  * the purpose of the raspberry model (why you cannot use a single large particle instead)
  * how the ions are modeled


## Learning objectives (ESPResSo)

After the tutorial, students should be able to

* set up a raspberry model using virtual sites
* explain to a new ESPResSo user the concept of `VIRTUAL_SITES_RELATIVE`


## Points to mention throughout the tutorial

* Explain how the number of surface beads is determined: one per lattice unit area.
* Explain the concept of hydrodynamic radius.
* There is also a GPU variant of the P3M algorithm.

