Dedicated to state-of-the-art time-resolved research in biological and physical sciences.


BioCARS micro-spectrophotometer for on-line and off-line recording of optical absorption spectra of crystals, to aid X-ray diffraction studies.

Laser Lab

BioCARS ps laser system: Spectra Physics, Ti:Sapphire Spitfire Pro 5 (780nm, 2ps, 1kHz, 5mJ/pulse) and TOPAS OP

14-ID Beamline

BioCARS 14 ID beamline provides necessary infrastructure for conducting state-of-the-art time-resolved X-ray scattering studies with 100ps time resolution, both in biology and in physical sciences.

Laue X-ray Diffraction Pattern

Laue diffraction pattern collected at 14 ID from a Scapharca Inequivalvis tetrameric hemoglobin crystal, as part of 100ps time-resolved studies.

Update on Status at BioCARS, February 1, 2021

Dear BioCARS Users,

Given the current state of the COVID-19 pandemic, the APS user program is currently operational to support:
– Mail-in/remote access work for any research involving low-risk samples and most medium-risk samples as defined on the Experiment Safety Assessment Form.
– Experiments proposed by users with prior APS experience that cannot be performed remotely and that meet specific criteria. These proposals will be considered on a case-by-case basis with no guarantee of approval. Contact for more information.

Please contact BioCARS staff scientists to discuss feasibility of your experiments in the current APS operations phase.
For latest APS operational announcements, please check APS home page or the User Info During the COVID Pandemic page.

Our Mission

BioCARS is a national user facility for synchrotron-based, dynamic studies in structural biology, located at Sector 14 of the Advanced Photon Source, at Argonne National Laboratory. BioCARS is an integral part of the multi-disciplinary Center for Advanced Radiation Sources (CARS) run by the University of Chicago.

Structural biology at BioCARS is supported by the National Institute of General Medical Sciences of the National Institutes of Health under grant number P41 GM118217.

The mission of BioCARS is to provide state-of-the-art X-ray facility, scientific and technical expertise and support to enable users to study the dynamic properties of biological macromolecules by X-ray scattering techniques: time-resolved diffraction and solution scattering (SAXS/WAXS). In hybrid mode of the APS storage ring, BioCARS 14-ID beamline provides high polychromatic flux, with a number of photons per 100ps pulse approaching that of free electron lasers (such as the LCLS). Short X-ray pulses are synchronized with ps or ns laser pulses for conducting pump-probe time-resolved experiments. Laser pulses are used to initiate reactions in naturally photo-sensitive proteins or in other proteins that can be used with a suitable caged compound, and to initiate temperature or pH jumps. We are currently developing methods and technology for serial Laue micro-crystallography in order to facilitate studies of irreversible reactions while minimizing sample consumption. Another exciting field we are focusing on is the development of electric-field jump as a method for reaction initiation and studies of protein dynamics. The overall goal of time-resolved experiments our users conduct is to understand basic biological processes in structural and dynamics terms, on time scales from 100 picoseconds to seconds.

BioCARS operates two Experimental Stations, embedded in a Biosafety Level 3 (BSL-3) Facility. This BSL-3 synchrotron-based capability is unique in the United States and permits safe studies of biohazardous materials such as pathogenic human viruses.
*As of February 6, 2017, BioCARS facility is decommissioned as a BSL-3 laboratory. BioCARS is now approved for research up to the BSL-2 level.

Quick Links

Recent Publications

Hsu, D. J., Leshchev, D., Kosheleva, I., Kohlstedt, K. L., and Chen, L. X. (2021)
Unfolding bovine α-lactalbumin with T-jump: Characterizing disordered intermediates via time-resolved x-ray solution scattering and molecular dynamics simulations.
J. Chem. Phys. 154, 105101.

Henry, L., Berntsson, O., Panman, M. R., Cellini, A., Hughes, A. J., Kosheleva, I., Henning, R., and Westenhoff, S. (2020)
New Light on the Mechanism of Phototransduction in Phototropin.
59, 3206–3215.

Ren, Z., Wang, C., Shin, H., Bandara, S., Kumarapperuma, I., Ren, M. Y., Kang, W., and Yang, X. (2020)
An automated platform for in situ serial crystallography at room temperature

Henry, L., Panman, M. R., Isaksson, L., Claesson, E., Kosheleva, I., Henning, R., Westenhoff, S., and Berntsson, O. (2020)
Real-time tracking of protein unfolding with time-resolved x-ray solution scattering.
Structural Dynamics 7, 054702.

Kim, T. W., Lee, S. J., Jo, J., Kim, J. G., Ki, H., Kim, C. W., Cho, K. H., Choi, J., Lee, J. H., Wulff, M., Rhee, Y. M., and Ihee, H. (2020)
Protein folding from heterogeneous unfolded state revealed by time-resolved X-ray solution scattering.
Proc. Natl. Acad. Sci. U.S.A. 117, 14996–15005.

Kim, H., Kim, J. G., Muniyappan, S., Kim, T. W., Lee, S. J., and Ihee, H. (2020)
Effect of Occluded Ligand Migration on the Kinetics and Structural Dynamics of Homodimeric Hemoglobin.
J. Phys. Chem. B 124, 1550–1556.

Thompson, M. C., Barad, B. A., Wolff, A. M., Cho, H. S., Schotte, F., Schwarz, D. M. C., Anfinrud, P., and Fraser, J. S. (2019)
Temperature-jump solution X-ray scattering reveals distinct motions in a dynamic enzyme.
Nat. Chem. 11, 1058–1066.

Latest News and Highlights

BioCARS Starts a New Zoom Seminar Series

During these times of COVID-19 restrictions, when most BioCARS users cannot travel to BioCARS to conduct their experiments, we deemed it essential to continue regular communications and scientific discussions with our user community. We decided to start BioCARS Zoom...

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High-viscosity injector-based pink-beam serial crystallography of microcrystals at a synchrotron radiation source

Martin-Garcia, J. M., Zhu, L., Mendez, D., Lee, M.-Y., Chun, E., Li, C., Hu, H., Subramanian, G., Kissick, D., Ogata, C., Henning, R., Ishchenko, A., Dobson, Z., Zhang, S., Weierstall, U., Spence, J. C. H., Fromme, P., Zatsepin, N. A., Fischetti, R. F., Cherezov, V., and Liu, W. High-viscosity injector-based pink-beam serial crystallography of microcrystals at a synchrotron radiation source. IUCrJ 6, 412–425 (2019)

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Unfolding Bovine α-Lactalbumin with T-Jump: Characterizing Disordered Intermediates via Time-Resolved X-Ray Solution Scattering and Molecular Dynamics Simulations

Unfolding Bovine α-Lactalbumin with T-Jump: Characterizing Disordered Intermediates via Time-Resolved X-Ray Solution Scattering and Molecular Dynamics Simulations

The protein folding process often proceeds through partially folded transient states. Therefore, a structural understanding of these disordered states is crucial for developing mechanistic models of the folding process. Characterization of unfolded states remains challenging due to their disordered nature, and incorporating multiple methods is necessary. Combining the time-resolved x-ray solution scattering (TRXSS) signal with molecular dynamics (MD), we are able to characterize transient partially folded states of bovine α-lactalbumin, a...

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An Automated Platform for in Situ Serial Crystallography at Room Temperature

An Automated Platform for in Situ Serial Crystallography at Room Temperature

Direct observation of functional motions in protein structures is highly desirable for understanding how these nanomachineries of life operate at the molecular level. Because cryogenic temperatures are non-physiological and may prohibit or even alter protein structural dynamics, it is necessary to develop robust X-ray diffraction methods that enable routine data collection at room temperature. We recently reported a crystal-on-crystal device to facilitate in situ diffraction of protein crystals at room temperature devoid of any sample...

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