Who can apply?

PNCC resources are open to everyone in the global scientific community who wants to learn CryoEM. Access is given out based on peer reviewed proposals. Please contact our user office with submission questions.

If a lab has access to a local imaging facility are we still able to apply?


What do you provide?

PNCC provides access to high-end CryoEM equipment and diverse training activities (sample preparation, microscope operation and data processing). For more information, visit our about us page.

What does it cost?

No cost for services and training.

How do I sign up for announcements?

We generally announce on twitter and cryoEM mailing lists (3DEM, CCPEM, and CCP4BB). We encourage you to join one of those mailing lists if you are not already a member so that you do see our posts and also become part of the greater cryoEM community.


PNCC is out of modified operations starting March 2022. We are accepting proposals on a monthly basis, accepting remote requests and in March 2022, on-site requests. Please see our scheduling policies if you are wondering about sample preparation.

Can international institutions apply?

PNCC recommends that potential users from international locations try to contact a closer resource. Please see our resource page of current international and national cryoEM center's that we know of. If you do not see a resource listed here, PNCC accepts international applications, in addition to US applications.

Is my project ready for CryoEM?

PNCC recommends reading this review by Liz Kellog and Michael Cianfrocco. Additionally, check out CryoEM 101 by Peter Shen and Janet Iwasa.


Proposal Submission

What are the proposal deadlines?

All proposals are sent for review monthly and are due by 11:59 p.m. on the 1st of the month. 

What is required for submission?

Visit Choose an Access Type under step 3 on the Access webpage. There are submission details for each proposal type.

What is involved with the renewable increments?

General Access proposals receive up to 480 hours given in allocations. With a General Access proposal, you can pre-apply for more time after you have used 60% of your allocated hours by submitting an General Access Extension early. You can also use this form if your hours have expired or are near expiring. In addition to requesting additional hours, users can add up to five samples, which are restricted to samples that align directly to the original proposal and builds upon the prior samples. All samples will be checked by our co-director, Claudia López. Any samples that are found to be outside the scope of the proposal will not be approved to be shipped on-site. 

Should I include preliminary data?

Yes!  Please include any preliminary data that can help reviewers establish project feasibility and staging.  Suggestions include: SDS-PAGE gels, SEC traces, SEC-MALS, DLS, negative stain TEM or cryo-TEM images. If your proposal is missing preliminary data it may receive a limited allocation of hours restricted to sample optimization and screening. We provide screening services at PNCC to get high quality preliminary data.

What biosafety levels are accepted?

Please see our Usage Disclaimers webpage, "PNCC Biohazard Information" for more information regarding sample biosafety.

What happened to the 'Limited Access' mechanism?

The Limited Access mechanism has been consolidated into the General Access mechanism, which provides initial allocations of 24-120 hours of microscope time are awarded based on the project scope and external peer review. Those seeking to access the PNCC for projects of limited scope are welcome to apply through the general access mechanism.

How do I edit my proposal?

Please email our user office with any questions regarding editing proposals, including adding/removing users.

When will my proposal be approved?

It takes approximately forty-five days from the proposal deadline for a proposal to be approved. If it has been longer than this, please email our user office.

How do I see my proposal score and review comments?

In the PNCC User Portal, select proposal, on new page select “Peer Reviews.”

When does my time expire?

General Access can last for up to two years, but each allocation expires in six months if not used. Screening Access lasts up to four months.

How many proposals can I have?

There is no limit to the number of General Access proposals a Principle investigator may have as long as the science focus is distinct and non-overlapping.



Is there a user onboarding?

Yes, if the proposal is approved, our user office will cover an initial one-hour user presentation capturing: points of contact, required paperwork, proposal hours, microscopes, samples shipping, scheduling, surveys, and publications.

How do I get training?

Approved General Access proposals can attend more workshop trainings compared to the general public. Please see our Workshops to view the list of training we currently offer.

How do I apply for more hours?

If you have a General Access proposal, then you will need to submit an General Access Extension. With a General Access proposal, you can pre-apply for more time after you have used 75% or more of your allocated hours by submitting an General Access Extension early.

Can I add more samples?

You can only add more samples to a General Access proposal during an General Access Extension. During this time, you can add up to five samples, which are restricted to samples that align directly to the original proposal and builds upon the prior samples. All samples will be checked by our co-director, Claudia López. Any samples that are found to be outside the scope of the proposal will not be approved to be shipped on-site. 

How do I add more participants?

PI's can contact the user office to get participants added and removed. New participants will need to create a PNCC User Account before being added. All participants are required to acknowledge an agreement.

Is there a limit to participants?

Not at this time. Our proposal types are setup to have a "main" PI, co-PI(s), and any number of participants. If anyone in your laboratory will be contacting about an approved proposal, we will require them to be added to the proposal in order to communicate with them.



How do I schedule microscope or training access once my project is awarded?

You must have a PNCC User Agreement on-file signed in the PNCC User Portal (and an Badge Form for on-site visits). See step 2 on the Access webpage for more details. Once your paperwork is completed, you can schedule experiments.

How many people from our proposal can we send for an on-site visit?

There is a limit of two users visiting on-site. Contact our user office.

Can I setup my own data collection?

Yes, please refer to our scheduling policies regarding independent user. PNCC staff will load all grids.

Can I have multiple reservations?

Yes, but please be aware of our cancellation policy in our scheduling policies.

What is the minimum and maximum time to schedule?

Please review our scheduling policies "Screening Services" and "Data Collection Services."

When will our scheduling request be scheduled?

Once your samples have been received and are ready to be loaded on the microscopes with no other holds, we will schedule your request. In general, our wait times range from 2 to 8 weeks for microscope time.

Why is my scheduling request being skip over?

We assure you that your request is not being skipped over. Please note that our facility is limited to 5 working days-a-week when scheduling, therefore, we are limited on the number of requests we can schedule per week. Long data collection requests (>48 hours) might experience longer waiting times.  Typically 24hr requests are the fastest to schedule. Additionally, having requests for specific microscopes can cause a delay in your request being scheduled.

Generally, when all of our microscopes are running optimally, we schedule a total of four, 72hr requests a week, flanking with 48hr and 24hr requests as we can fit. If our microscopes are not running optimally this can cause rescheduling of already booked requests. PNCC reserves the right to modify schedules and queue traversal if needed to adapt and best utilize instrumentation. Changes to requests may require changing dates or position in the queue.

How do I get Krios time?

Go to schedule experiments and place a scheduling request for data collection. Samples must be pre-screened before requests for Krios time are accepted, with preliminary data required when submitting the request. Visit Shipments under step 3 on the Access webpage for PNCC Pre-Screened Grid Form.

What is considered a pre-screened grid?

Visit Shipments under step 3 on the Access webpage.

Where do I send pre-frozen grids?

Visit Shipments under step 3 on the Access webpage.

Can we send grids in a storage puck?

Visit Shipments under step 3 on the Access webpage.

How many grids can I send?

Visit Shipments under step 3 on the Access webpage.

Will you clip my grids?

Please review our scheduling policies "Grid Preparation Services."

Can I bring my samples on-site to be vitrified at PNCC?

Visit Shipments under step 3 on the Access webpage.

Can I send other samples than what is listed in my proposal?

Visit Shipments under step 3 on the Access webpage.

Where can I leave feedback?

You can submit a Microscope Session survey. At the end of your proposal, we will send a National Institutes of Health required 'End of the Project' survey for you to fill out. You can also contact us with specific feedback.


Get Data

How do I get my data?

We offer Globus, MinIO (testing), ARIA2, and the PNCC User Portal. Globus is required on all applications. More information is at Download Data under step 4 on the Access webpage.

Can we use rsync?

Unfortunately, rsync is prohibited by an institutional firewall on our end, so is not an option. ARIA2 is available as a command line based parallel download manager. See the "How do I get my data" section above for details about ARIA2 and contact the Data Team directly if you have questions with its implementation.

Can we send hard drives?

Yes, but this must be approved by support before shipping hard drives to our facility. We prefer data to be transferred via one of the options listed above, but do make exceptions for projects where the institution is far from the center, has very poor transfer rates and has large datasets. 

What are my imaging parameters?

For all DATA COLLECTION sessions, a "METADATA_INFO.txt" file is automatically created within 30 minutes of the session data appearing on PNCC compute resources. This "METADATA_INFO.txt" contains all relevant parameters including Cs value, accelerating voltage, pixel size, exposure dose, etc. Keep in mind, that the pixel size value is coming from the cross-grating grid and can be a few % off, contact your SPOC before processing the data to get an accurate value (calibrated on the standard protein dataset). The metadata file can be found at the same directory level where you will find the "frames/" folder and the "relion3_preprocess/" folders containing your raw images and preprocessed data. Open the "METADATA_INFO.txt" file with any text editing program. Please contact your SPOC with any questions about the specific parameters or the Data Team directly if the file can not be found for some reason in your data directory. Note, the metadata file is not created for screening sessions. 

Can I upload data to PNCC Compute?

No, per NIH, users are only allowed to work with data collected at PNCC only. We do not allow to process the data or upload of raw data collected elsewhere. Even if is the same protein sample or if combining datasets will help you to complete the project. You are however, allowed to bring masks and initial 3D volumes.


     After Award

    What should I do when I publish?

    Please see our Usage Disclaimers webpage, "PNCC Use Terms: Data Sharing & Publications" for more information regarding publications.

    Do I list PNCC Proposal(s) in NIH documents?

    Yes, PNCC Proposals should be included in NIH Other Support and NIH Biosketches for grant application as of January 25th, 2022. PNCC does not provide support letters. However, PIs can describe the process to apply for a PNCC Proposal in applications at the facilities/equipment section of grant applications, if desired.

    Please use these resources for more information: