Member institution guidelines for application:

Glacios screening is closed for 2024! We have limited availability on our waiting list in case of cancellations. We cannot guarantee that we’ll be able to serve you before the end of the year. We will resume normal booking in January 2025.

The TFS Glacios electron microscope features a 200 kV XFEG optics and an autoloader capable of holding 12 grids, and has the same automation for ease of use as the Krios TEM.
MEMC users may apply for staff-assisted access to the system by completing a short application [Applications are closed until 2025]. Grids will be screened by our Glacios operator during business hours, or a small dataset (~1000 images) can be automatically collected overnight. The user’s presence is recommended to observe the session’s progress. We also offer Smart Leginon, a program that loads & unloads all grids, collects images at each magnification through machine learning and computer vision algorithms to identify and rank squares and holes, allowing the system to automatically identify and select likely targets of interest, while avoiding empty holes or ice contamination.

Once your session has been scheduled, you’ll complete the Grid Drop Off Form. This is mandatory or your session will not start! This form gives the operator important information about how to set up your session. You’ll also be able to opt out if you don’t want us to use your anonymized images for research and education efforts. This will not affect your session.

We guarantee four grids per manual screening session. You may request more grids to be screened during manual screening if the additional grids are clipped prior to drop off. Pending availability of the scope, your request may be denied or split over multiple sessions.

*We offer only four complimentary clippings*

Glacios screening: 

  • What we do: Screening sessions are the most common sessions on the Glacios microscope. MEMC users may be scheduled for Tuesday, Wednesday or Thursday screening (if you need a different day, let us know in your application and we *may* be able to accommodate you). Screening may be used for two purposes: to test sample preparation conditions, or for validation of Krios readiness. In both cases, a small atlas of each grid will be made. Four grid squares of varying sizes (i.e., various ice thickness) are selected. Four exposures are made in each square, for a total of sixteen exposures per grid. 

Each grid takes ~25 minutes from loading to the last exposure. Grids may run for longer or shorter times depending on grid quality and microscope stability. 

  • What you learn: From these sixteen images, we can monitor particle distribution and ice quality. We will be able to see what kind of squares tend to have the best particles (ideally, soluble and close together) and ice. We will also be able to find issues like protein aggregation, crystalline ice, holes with no ice, and no protein. When you make your next batch of grids, you’ll have a good idea of which problems to solve. Or, if you have lots of good-looking squares, we can help you decide if your grids have enough of them to be Krios-ready. 

If you are happy with your sample prep conditions and ready for the Krios, we will check your grids to make sure they are as expected- even duplicate grids can look very different from each other.

With only sixteen exposures per grid, we won’t be able to look at particle orientation. You’ll need to run an overnight data collection for this. 

Glacios data collection: 

  • What we do: We will set up an overnight data collection on one of your screened grids. Typically we collect about 1000-2000 exposure images. This data set is optional. Its main purpose is to assess particle orientation and see what 2D classes look like. We will set up a cryoSPARC Live session with these images. If you want us to run an overnight data collection, please note it in your Glacios Application.
  • What you learn: Overnight data collection is especially useful if you have small proteins that just look like little dots in the micrographs, or you want to see if you have enough particles in a particular conformation or ligand occupancy state. Your next step might be to submit that grid and some duplicates for Krios data collection, or continue to optimize for a desired conformation, orientation, etc.