National Cancer Institute - Cancer.gov

SAXS Core Facility: User Policies

1. Authorship and Acknowledgement

The SAXS Core facility is a CCR resource dedicated to the CCR researchers. But we also make this resource accessible to non-CCR users free of charge. There are three ways to make use of the SAXS Core resource.

  1. Asking the SAXS Core staff to collect, process, and analyze data, and jointly interpret data with your teams.
  2. Asking the core staff to collect data and send it to you.
  3. Sending your teams to use the beamline resource and to collect, analyze and interpret data independently without input from us.

Like any institution, the SAXS Core is subject to annual reviews based on its performance and impact on the community in terms of a number of criteria. Thus, the success of SAXS Core highly depends on the strong support of the user community. Whenever the staff makes intellectual contributions to your research projects, such as collecting data, and/or processing data, authorship for whoever contributes is appropriate. In all cases, the use of the beamline and the people who inevitably help with data collection at the beamline resource should be acknowledged.

An example of acknowledgment

For the SAXS experiments, we gratefully acknowledge the use of the SAXS Core facility of Center for Cancer Research, National Cancer Institute (NCI). The SAXS data were collected at beamline 12-ID-B. The shared scattering beamline 12-ID-B resource is allocated under the PUP-24152 agreement between the National Cancer Institute and Argonne National Laboratory (ANL). We thank Dr. Lixin Fan (NCI), and Dr. Xiaobing Zuo (ANL) for their expert support. Use of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, was operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

2. Beamtime Request

You should first become a CCR SAXS Core facility user to be eligible for a beamtime request. Please refer to "Becoming a Core Facilities User". Your Principal Investigators or Supervisors must contact the core staff and authorize the use of the CCR SAXS Core resource.

Synchrotron SAXS/WAXS Beamtime Request

You will receive a synchrotron beamtime notice through emails. Fill out the sample information form and send it to Dr. Lixin Fan (Lixin.fan@nih.gov) at least 10 days before a beam time. Please notify if you plan to come to the APS beamline, or come to the beamline to collect data by yourselves. Dr. Fan will collect the sample information from all the users and fill out the ESAF form and submit it to APS. In the sample information form, you must disclose the hazardous status of your samples such as biohazardous, chemical hazards, radioactive, etc. You can download the sample information form at User Support. Please notify Dr. Fan as soon as possible if there is a cancelation of your experiment.

In-House SAXS Beamtime Request

To request a beam time of the in-house SAXS Instrument, please check the online Instrument Schedule and follow the instructions posted there. Your name and beam time allocations will be put on the schedule by SAXS core stuff. If a preliminary discussion of the scientific problem or training is required, contact Dr. Lixin Fan by e-mail or by phone/voice-mail at 301-846-1362 (Bldg. 538/124). Please notify the SAXS Core personnel as soon as possible if you need to cancel or postpone a previously arranged appointment.

Beamtime Allocation Policy

The allocation of SAXS Core beamtime will be prioritized based on a number of factors. The projects initiated by the CCR PIs take the highest priority, then intramural NIH researchers and extramural researchers from other organizations. Within the same priority group, beamtime is allocated mainly based on the order that it is requested. In the meantime, beamtime is also allocated and users are grouped to make the most efficient use of the instrument based on required beamline settings. The SAXS Core facility staff reserves the right to allocate time at their discretion in order to balance the needs of users and the availability of the beamtime.

3. Samples Protocols

  1. The sample preparation guide and sample volume requirement for synchrotron SAXS/WAXS and in-house SAXS measurements can be found at User Support. The most common problem at the beamline is aggregation in the sample. Since larger particles scatter X-rays more strongly than small particles (albeit less than visible light scattering), the aggregation will bias the results. We strongly recommend doing DLS, and native gel, or gel filtration (best) before SAXS measurements. If your sample has a tendency to aggregate over time, you can prepare the sample at dilute concentrate and then concentrate just prior to data collection at the in-house SAXS instrument.
  2. Label sample tubes uniquely so that when they are stuck in the refrigerator with many other tubes, they don't get lost. Recommend sample name and concentration on the top of the tubes and your initials with a number (for example, YW1) and date of sample on the side of the tubes.
  3. Sample shipping and drop/off address.

For measurements at a synchrotron, you should ship your samples directly to APS. The shipping address is:

  • Lixin Fan, Ph.D.
    c/o Xiaobing Zuo, Ph.D.
    Building 433-E030
    Chemical and Materials Science Group X-Ray Science Division
    Argonne National Laboratory
    9700 South Cass Avenue
    Argonne, IL 60439
    630-252-1553

For measurements on the In-house SAXS instrument, you should ship or drop off your samples to:

  • Dr. Lixin Fan
    The Small-Angle X-ray Scattering Core Facility
    Center for Cancer Research
    National Cancer Institute
    1050 Boyles St, Bldg 538, Rm. 124
    Frederick, MD, 21702
    (301) 846-1362

4. Training

Safety Training

All researchers must complete lab safety training before using any SAXS instruments. The safety training for working at APS beamline will be provided by APS beamline scientists. The safety training for working at the In-house SAXS beamline/instrument will be provided by Dr. Lixin Fan.

All researchers must complete lab safety training before using any SAXS instruments. The safety training for working at APS beamline will be provided by APS beamline scientists. The safety training for working at the In-house SAXS beamline/instrument will be provided by Dr. Lixin Fan.

Instrument Training

The use of the BioSAXS-2000 instrument requires training by Dr. Lixin Fan. Previous training on a similar instrument is not necessarily adequate. The training will include data collection and data processing either on a synchrotron SAXS beamline or on the In-house SAXS beamline/instrument. All users that have a lapse of 3 months or more in their usage of the instrument MUST FIRST e-mail (Lixin.fan@nih.gov) to schedule refreshment training to reinforce their operation skills. The core staff will be the only authorized personnel to train users.

All users that have a lapse of 3 months or more in their usage of the instrument MUST FIRST e-mail Dr. Fan to schedule refreshment training to reinforce their operation skills. The core staff will be the only authorized personnel to train users.

5. Working Hours

The regular working hours for In-house BioSAXS are Monday-Friday 9:00 am-5:30 pm. After-hours access is available with the permission of SAXS core staff.

6. Using Facility Instruments

  • You are eligible to work on the instrument only after receiving instrument operation and safety training from the SAXS Core stuff/APS beamline scientist and signing the form of training completion.
  • Newly trained users will need to schedule their work initially only during working hours (9:00 am-5:30 pm) in order to get help from staff members if needed.
  • Your usage is limited to data collection and sample changes only. Any modification of hardware and software is not allowed without permission from the staff.
  • For use of a synchrotron beam, if more than one person will be using the beamline over the course of the assigned time one spokesperson must be present during the entire shift. All users must be authorized users.
  • Bringing along a colleague to accompany authorized users during the work on the Core Facilities instruments is not allowed due to radiation safety requirements.
  • There is a 24-hour cancellation policy for beamtime. Any instrumentation session not started within 1hour after the scheduled start time is subject to cancellation.
  • Please notify the Core staff to receive prior approval to use hazardous substances.
  • Sign in on the instrument using the Log file (in Excel format, locates on the desktop of the experimental control computer) at the beginning of your session and sign out after you complete the measurements. Make note of any problems in the Log file.
  • Report all breakages and major problems (those that seriously disrupt normal operation) to SAXS Core staff as soon as possible. Troubleshooting can be difficult or impossible if the lab session has been terminated by the user such that symptoms are no longer diagnosable. It is not acceptable to simply type a message into the comments field of the Log or just list the problem in the notebook and walk away!
  • Clearly label all samples and hazardous waste with the date and your name.
  • Do not leave samples or chemicals on lab benches.
  • It is your responsibility to save and copy your data to your own USB/ external drive.
  • Clean all your stuff after your measurements are done.
  • If you finish early please notify the SAXS Core staff. Do not transfer or share your beamtime with other users without prior approval from the SAXS Core staff.