VariMax optics and a collimator produce a 0.3 mm X-ray beam with adjustable divergence for the optimal separation of Bragg reflections on the R-AXIS IV++ imaging plate area detector (shown in background).
Macromolecular crystallization experiments may be set up using the Thermo Scientific Matrix Hydra II Plus One, a specialized liquid-handling robot.
Instrumentation in the X-ray Crystallography Core includes:
Rigaku MicroMax-007 X-ray generator with inverse-phi goniometer and an R-AXIS IV++ imaging plate area detector. This system is optimized to provide not only high X-ray flux through small crystals for maximum in-house diffraction, but also superb data from larger crystals. While the optimal crystal size is 0.3 mm3, well-ordered crystals of 0.05 mm3 are sometimes used.
The system has VariMax Confocal Max-Flux optics that maximize X-ray flux and aid in data collection from crystals containing very large macromolecules. There is a 2-theta stage for extremely high-resolution data collection and an X-stream 2000 low-temperature device for reducing radiation damage and slowing thermal atomic motion.
- Thermo Scientific Matrix Hydra II Plus One robot. This instrument is used for the setup of crystallization boxes, though other applications requiring a fluidics robot also are possible. For example, DNA plasmid prep and PCR formatting protocols have been tested and performed. This robot is also used to set up protein-fragment library microplates for drug discovery research. Protein samples can be kept cold during operation.
Beckman Avanti J-20XP centrifuge. This 26,000-RPM instrument is ideal for pelleting bacterial, yeast and insect cell cultures, as well as for separating or concentrating cellular subfractions or macromolecules. This centrifuge can easily process 6 liters in 10 minutes.
The core has two rotors available. The first is a 6-liter (6 x 1,000 mL), fixed-angle JLA-8.1000, 8,000 RPM, 15,970 x g. The second is a 400-mL (8 x 50 mL), fixed-angle JA-25.50, 25,000 RPM, 75,600 x g, with a dual-locking lid.
Two Innova 4430 incubator shakers/refrigerators. These large-capacity instruments are used for bacterial, yeast and insect cell cultures, and offer dual-temperature programming to automate switching between two temperatures on a programmed basis.
Their temperature range is from 15 degrees Celsius below ambient temperature to 80 degrees Celsius. It can agitate at 25 to 400 RPM with a 1-inch stroke and 25 to 300 RPM with a 2-inch stroke. Within each of the core's two incubators, clips are presently installed for 12 2-liter flasks, one 250-mL flask and one 50-mL flask.
Agilent 8453 UV-Visible spectrophotometer. Using a photodiode array, this spectrophotometer can simultaneously measure — with only a one-millisecond dead time — the ultraviolet to visible light spectrum. Results are very reliable and repeatable.
Spectrophotometer accessories available in the core include:
- Agilent 89090A Peltier temperature controller. This instrument includes a digital controller with LED display for preheating samples from 10 to 100 degrees Celsius. The unit includes a heat exchanger and magnetic stirrer controller, and its temperature can be set in Celsius, Fahrenheit or Kelvin.
- Agilent G1120A multicell transport. This piece of equipment includes a water thermostattable eight-position cuvette holder for standard 1-cm cuvettes, as well as provisions for attaching a water bath with temperature-regulated circulating water.
With permission, collaborators may make use of additional equipment and supplies that belong to the independent research laboratory of James R. Thompson, Ph.D., core director. But as such usage is not included in Dr. Thompson's budget, there may be some costs involved to restock items.
X-ray Crystallography Core users also have access to additional crystallization and crystallography instrumentation, which was funded through two Minnesota Partnership for Biotechnology and Medical Genomics grants, located in the Nanoliter Crystallization Facility and the Kahlert Structural Biology Laboratory at the University of Minnesota. Contact Dr. Thompson for more information.