Cryo-EM Facility usage rules
Updated: June 2025
Note: These procedures are subject to change based on user and staff feedback. All current and prospective users are responsible for staying informed of the latest guidelines.
General User Guidelines
- If you are feeling unwell, please do not attend your session in person. Facility staff can operate the microscope on your behalf and provide remote monitoring.
- A maximum of three people are allowed per microscope session, including any facility staff involved.
- A maximum of three people are allowed per Vitrobot session, also including any facility staff present.
- Users are required to clean all surfaces and properly dispose of waste at the end of their session.
- Repeated disregard for procedures or misuse of bookings may lead to suspension of facility access, at the discretion of the Facility Manager.
- We do not tolerate physical, verbal or written abuse of our staff. Please treat them with respect. Aggressive, violent or abusive behaviour will not be tolerated and may result in your services being restricted.
Microscopes
- Users are required to book microscope sessions directly via the online booking system.
- Bookings may be made no more than 30 days in advance and no fewer than 1 day before the session.
- Users must email the Facility Manager at least 3 days in advance with the list of grids to be loaded for their session, including their locations.
- Bookings cannot be cancelled within 3 days of the scheduled session. Users will be charged in full, regardless of attendance or session usage.
- Facility staff reserve the right to modify or cancel bookings at short notice due to technical issues, maintenance needs, or operational priorities. Users will be notified promptly.
- Facility staff may conduct grid screening or data collection sessions without the user present. In such cases, all communication will be conducted electronically.
- Interactive microscope sessions typically start at 9:00 AM and must conclude by 4:00 PM. The actual data collection must start not later than 3:30 PM.
- A maximum of 11 grids (i.e. one full cassette) may be loaded per Talos session and 6 grids per Titan session. The number of grids actually screened will depend on the session's end time (setup must finish by 4:00 PM).
- At least one pre-screened grid should be loaded into Titan.
- A second cassette may be loaded on the Talos Arctica, but the decision must be made by 12:30 PM. In this case, no overnight data collection will be set up.
- Overnight data collection will be stopped at around 7:00 AM the next day.
- The Titan Krios allows for multiple data collections using the multi-grid EPU feature. Please note: the Facility does not guarantee performance or provide active monitoring during automated runs.
- Weekend sessions are available on the Titan Krios. Use of the Talos Arctica over weekends requires prior approval from the Facility Manager.
- External users must deliver their grids at least three days before the scheduled session. Failure to do so will result in cancellation without refund.
- If users require their grids to be clipped, they must email clear instructions - including grid locations, the number of grids to be clipped, and the desired timeline - at least 3 days prior to their microscope session.
- Remote operation or monitoring of microscopes by users is not supported.
Vitrobots
- Vitrobot 1 and Vitrobot 2 are located in Room 00.05, along with the glow discharger.
- Only trained by Facility Staff users can use the Vitrobots.
- Clean gloves, safety specs and lab coats must be worn at all times in the facility.
- The default session duration is 2 hours, with 1 hour 45 minutes allocated for use and the final 15 minutes reserved to avoid session overlap.
- A new safety procedure for ethane condensation is in place. Contact Lee Cooper (lrc44 at cam.ac.uk) for details.
- Use of the temperature-controlled dewar must be requested in advance by contacting Lee. Sessions must also be scheduled within Lee’s working hours.
- If users need Lee's help during their plunging session, they should book and plan to finish before 4 p.m.
- If users require facility staff to prepare grids for them, they should contact us in advance.
- Users must bring their own pipettes, pipette tips, pens, and other consumables.
- Users who cause damage to the vitrification tweezers beyond functional repair will be responsible for purchasing a replacement set.
- For grid storage buttons or tubes, please contact the Facility Staff in advance of your session.
Computational Resources
- Data will be stored on facility servers for at least 14 days from the start of your data collection session. After that, it will be deleted without further warning.
- For SPA (Single Particle Analysis) runs, data is routinely processed using WARP to assess microscope performance and validate collection parameters.
- Particle reconstruction using CryoSPARC can be performed by the Facility staff if time permits and with prior agreement. This is not a routine service. All non-routine tasks must be properly acknowledged, in accordance with the Association of Biomolecular Resource Facilities (ABRF) guidelines.
- Processed data from WARP or CryoSPARC may be deleted immediately after your session. If necessary, request a copy of the files in a timely manner.
Training
- Training is available to users from the University of Cambridge and affiliated institutions only.
- Vitrobot training is available on a one-on-one basis. Contact Lee Cooper (lrc44 at cam.ac.uk) with “Training” in the subject line.
- Microscope operation training is available to users who provide their own grids/samples.
- We do not currently offer “dry run” training sessions, except in exceptional circumstances.
- Contact Dima Chirgadze (dyc21 at cam.ac.uk) to arrange training as soon as your session is booked.
- Training sessions are limited to 6 grids.
- Training on the Titan Krios is only available after the user has completed training on the Talos Arctica.