Perelman School of Medicine at the University of Pennsylvania

Electron Microscopy Resource Lab

Beckman Foundation

Services & Policies

SERVICES OFFERED

· The Beckman Center for Cryo-EM provides high resolution data acquisition on the Titan Krios microscope located in the Basement of the Singh Center for Nanotechnology.

· The facility houses a Titan Krios microscope, phase plate, Gatan K3 Summit Direct Detector, Bioquantum GIF energy filter, Vitrobot cryo plunger, and all accessories needed to perform sample preparation for cryo-EM.

· The facility is currently restricted to facility staff for operation and prescreened, Krios-qualified samples for data acquisition.

· The Cryo-EM data are collected and returned to the user.

· The facility does not provide cryo-EM data processing and reconstruction services.

· The use of the facility and contributions of the staff must be acknowledged in the “Materials and Methods” and “Acknowledgment” sections respectively.

USAGE AND BILLING

· To qualify a sample/project for data collection on the Titan Krios, users must first submit an application for Krios usage that will be reviewed by the qualification committee on a monthly basis.

o Application for single particle cryo-EM: users must include, at least, cryo-EM pre-screening images from grids made from the same plunge freezing session (particles should be clearly visible) and 2D classification of their sample. If the application is successful, a Titan Krios time slot is granted. If necessary, the user can apply for an extension.

o Application for cryo-ET: users must include, at least, cryo-ET pre-screening images.

· Titan Krios Qualification Committee:

o Dr. Vera Moiseenkova-Bell (Faculty Director)

o Dr. Darrah Johnson-McDaniel (Manager)

· We offer the following data collection schedules in the Beckman Center for Cryo-EM: 2-6 days due to microscope and camera conditioning requirements.

· Facility staff hours are M-F 7:30-4:30 pm.

· Due to the complexities of the instruments, user error, or unforeseen circumstances, unplanned outages do occur potentially interrupting a user’s session. When this occurs, the billed usage will be rounded up to the nearest half-day. Furthermore, due to the complexities of trying to rearrange scheduling when outages occur, any user with an interrupted session will be given a new session at the next available time slot. We aim to minimize any downtime within our control.

· Cancelation policy: We understand that due to unforeseen circumstances a user might need to cancel or reschedule their session. When this occurs, we ask that the user provide the Beckman Center with at least 10 days’ notice so that we can fill the time slot. If the user wants to reschedule, they will be given a time slot in the next month.

DATA STORAGE AND ACCESS

· All University of Pennsylvania Beckman Center for Cryo-EM user data will be stored on the Blockley Hall data cluster for 48 hours after completion of data collection. After the 48-hour time period, the data will be deleted due to limited space on the cluster.

· All External Beckman Center for Cryo-EM user data will be stored on external hard drives that will be provided by the user.

 

CRYO-EM DATA COLLECTION WORKFLOW SCHEMATIC AND TIMELINE

· Once you have received confirmation that your data collection session has been approved, we ask that you complete the following checklist:

Clearly label your cryo-EM grids and deliver them to the facility

Set up a meeting with facility staff to discuss imaging conditions and data collection parameters

Acquire external hard drives with 20 or 40 TB space (if necessary).