PXI - X06SA: Macromolecular Crystallography
X06SA (PXI) is the first macromolecular crystallography beamline at the Swiss Light Source. It is equipped with a flexible two-stage focusing X-ray optics system and a single–photon counting hybrid pixel area EIGER 16M (Dectris) detector. X06SA is well suited for micro-crystals, crystallography of large unit cell structures, and single/multiwavelength anomalous diffraction experiments (SAD/MAD).
Beamline Characteristics
| Wavelength range (Å) | 0.7 - 2.2 |
|---|---|
| Spectral range (keV) | 5.7 - 17.5 |
| Energy resolution (%) | 0.02 |
| Flux at 12.4 keV at 400mA (ph/s) | > 2 x 1012 |
| Spot size h x v (μm) | Fast change from 5 x 5 to 100 x 100, option to focus on detector |
| Smallest focusing 10 x 1. Smallest beam 2 x 1 is available upon request | |
| Detector | EIGER 16M X (133 Hz) |
Beamline Features
Variable X-ray beam size, divergence, and focusing position
Control of beam size and divergence with a two-stage focusing X-ray optics and a movable secondary source position.
- Standard micro-focus 5 x 5 μm2 to 100 x 100 μm2 (user friendly one button control)
- Focus on detector (user friendly one button control)
- Micron-size beam, 2 x 1 μm2 (upon request)
EIGER 16M: the most powerful X-ray detector for synchrotron application
75 x 75 μm2 pixel size, 3.8 μs dead time, 133 Hz frame rate, maximum count rate 5x108 phs/s/mm2
- High sensibility with single photon counting and zero point-spread
- High spacial resolution to high diffraction resolution with smaller pixel
- Ultrafine-phi slicing with > 99% duty cycle, i.e. < 1% "non-recorded" photons
Left: one pixel resolution; right: high resolving power (1070 Å cell aixs)
Ultrafine-phi slicing
Continuous grid scan (up to 60 Hz)
- Diffraction-based alignment
- Fast grid-scan with micro-beam (micro-rastering)
- Wojdyla et al., J. Appl. Cryst. 49, 944 (2016) DOI:10.1107/S1600576716006233
SLS goniometer and scanning motions
64 sec grid scan with 10 x 10 μm2 beam on a whole LCP bolus (400 x 400 μm2)
One-micron beam grid scan (micro-rastering)
IMISX serial crystallography for membrane and soluble protein
- Eliminate the technically demanding and inefficient crystal-harvesting process in meso
- Harvest, freeze, store and transport IMISX wells in standard cryo pin, vial, puck and dewar
- Visualize micro-crystals in meso in cryo
- Huang et al. Acta Cryst. D71, 1238 (2015) DOI:10.1107/S1399004715005210; Acta Cryst. D72, 93 (2016) 10.1107/S2059798315021683
IMISX at room temperature
IMISX at cryogenic temperature
On-axis microscope view of crystals in IMISXcryo wells under cryojet at beamline
Serial synchrotron crystallography (SSX) software suite at PXI and PXII
- identification of well diffracting crystals with fast grid scan in DA+ GUI
- evaluation of grid scan results and automated collection of multiple minisets performed in the CY+ GUI
- automatic data processing (adp) of individual minisets
- automatic data merging (adm) of multiple minisets using the sxdm package
- automatic display of adp and adm results for the on-the- fly inspection (adp-tracker) and storage in the database (mxdb)
- Basu et al., J. Synchrotron Radiat., 2019, 26(1):244-252 DOI:http://doi.org/10.1107/S1600577518016570
The CY+ GUI with results of the grid scan heat map.
The adp-tracker ‘SX-View’ mode, with the adm merging results for 100 PepTSt crystals displayed.
TELL sample changer
- 20 seconds sample exchange time
- dry mounting, standard 18 mm SPINE pins
- Unipucks, NO SPINE pucks at 6S for use with TELL!!!
- dewar capacity: 30 Unipucks
SLS PX software
- easy and intuitive data acquisition with DA+ GUI
- robust DA+ data acquisition engine (DA+ server and Escape)
- SLS MX MonogDB database (so-called mxdb)
- automated data processing (adp) pipelines for single data set, multi-orientation data sets and serial crystallography data
- automated data merging (adm) for serial crystallography data with in-house sxdm pipeline
- Wojdyla et al., J. Synchr. Rad. 25, 293 (2018) DOI:10.1107/S1600577517014503
Schematic of SLS automatic data analysis