LS-CAT

About LS-CAT

The Life Sciences Collaborative Access Team (LS-CAT) provides macromolecular crystallography resources for those with a need to determine the structure of proteins. LS-CAT provides access to state of the art x-ray diffraction facilities at Argonne NationalLaboratory's Advanced Photon Source where intense beams of x-rays are focused onto tiny protein crystals using mirrors and beryllium lenses. The X-ray diffraction patterns created by this process are collected for a sample at multiple angles using high-resolution pixel-ray detectors. These diffraction images can be used to determine the structure of a protein in 3D space. Think of this process as similar to 3D photography, in that we can reconstruct a 3D image of an object by taking pictures of it at multiple angles. To obtain images of at such a small scale (smaller than the wavelength of visible light and even ultraviolet), we must use high energy X-rays. This allows us to reconstruct the shape of an individual protein in 3D space, making it possible to understand how different proteins interact with other molecules, enabling the discovery and invention of drug candidates to treat a wide variety of diseases.

LS-CAT was formalized in 2002 with seed money from the State of Michigan through the Michigan Core Technology Alliance. Northwestern University was selected as the managing partner, and personnel from the duPont-Northwestern-Dow Collaborative Access Team (DND-CAT) started work on the design of the facilities.

The LS-CAT facilities include three experimental stations using 2 insertion devices. The main beamline (21-ID-D) uses a shortened undulator and a Kohzu monochromator in a layout very similar to XOR Sector 4 and Northeastern Collaborative Access Team (NE-CAT), APS Sector 24.

In addition to the main beamline there are three experimental stations that share a single 3.0 CM undulator. The first two of these stations use diamond laue monochromators supplied by JJ X-Ray along with beryllium lenses to focus a beam monochromatic x-rays onto the sample. This allows SAD experiments to be done at the selenium edge (12.668 KeV). This arrangement is very similar to the ID14 beamline at the European Synchrotron Radiation Facility (ESRF).

Construction of the LS-CAT facilities started in January 2006 and completed in December 2006. 21-ID-D was opened for daily use collecting data for user experiments in January 2007.

Sadly, one of the driving forces behind the formation of LS-CAT, Martha Ludwig, passed away in late November, 2006, just days before the first x-rays were delivered at LS-CAT for its members. The experimental facilities at 21-ID are dedicated in honor of Martha Ludwig and also Michael Bolbat, who passed away in 2025 after serving LS-CAT since its inception as its chief machinist and electromechanical technician.