Robotic crystal harvesting is finally becoming reality

They said it would never work, but now it is becoming reality. Sponsored by a NIH STTR grant, a team of systems and robotics engineers at Square One Systems Design (Jackson, WY) and BR have designed and built the first semi-autonomous protein crystal harvesting robot. It performs all steps from crystal looping to cryo-protection, hyperquenching, and storage in cryo-pucks ready for shipment to the synchrotron. Additional room temperature mounting and diffraction characterization of the crystals is in development. 

The first demonstration unit has been installed in Spring 2011 at the Joint Center for Structural Genomics (JCSG) at the Scripps Research Institute in La Jolla, CA, wher it will be integrated in the Rigaku CrystalMation HTPX pipeline. The instrument is avialbale for demonstration at the Joint Center for Structural Genomics (JCSG). Please contact Bernhard Rupp or Marc Deller at JCSG if you want to visit and schedule a visit and try robotic harvesting.

Due to the modular design, the system can be exanded to include tool exchange, which allows for tasks extending beyond the conventional harvesting of protein crystals. The system is a true Universal Micromanipulation Robot (UMR). We presented the device at the first ever dedicated workshop on automated crystal harvesting at the National Synchrotron Light Source (NSLS) user's meeting in Brookhaven, NY, and at the recent NIH PSI Bottleneck meetings

Desktop harvesting station - based on the Robbins Instruments CrysCam - for the budget conscious

Key features of the robotic crystal harvesting system:

Ergonomic operation	Longer open well time	Hyperquenching and pin storage
Reduced operator fatigue	Sample well re-sealing	Crystal size down to < 10 micron
Increased overall efficiency	Universal drip-cryoprotection	Intuitive user interface

System design overview:

Serial robotic arm: The UMR is based on an anthropomorphic six-axis serial TX-60 robot arm by Stäubli, the Swiss world leader in precision robotics. The arm can be equipped witha tool exchanger providing enormous flexibility and extended operating capabilities.

Optics and lighting: High quality 0.75-3x (1:4) zoom optics as used on the proven CrysCam observing station provide nominal magnification of 144x exceeding the magnification of most stereo microscopes. Working distance of ~60 mm (>2 inches) allows comfortable sample access even at maximum resolution. Automated Z-drive (depth) for auto-focus features. Various custom lighting scenarios incuding backlighting, optimized for specific plates. 5 Mpix B/W camera interfaces to image recognition software.

X-Y sample stage: Custim designed stage accepts 96-well SBS standard plates. Slides out of cabinet for access, or can be automatically loaded in fully integrated system.

Digital image recognition: Crystals are automatically recognized and characterized by shape and size. The best crystal is automatically or user-selected, and the robot acquires a harvesting loop of the appropriate size. It then completes movement of the harvesting loop to a location immediately adjacent to the crystal. Once in position, the robot or user executes a pre-programmed capture routine that is distilled from typical operator-directed capture routines. After confirmation of successful looping, cryprotection, hyperquenching, and pin storage are autonomously conducted.

Sample access: A smart new tape punch cuts a small circular hole instead of removing the entire tape. This procedure not feasible by hand reduces evaporation losses and extends drop lifetime by about an order of magnitude. Compare both images of open wells after 15 minutes (tape removed vs. hole punched). A optional, new sealing station module allows to seal and preserve wells.

Drip cryo-protection and hyperquenching: A new drip-technique provides generally applicable cryo-protection by controlled dripping of low-viscosity perfluoroether from a solenoid valve onto the looped crystal - no, they do not wash off!  Watch the movie (listed below). The sample is the hyperquenched (Warkentin et al) assuring the fastest achievable quench rates.

Small is beautiful: The positional repeatability of the robot arm below 1 micron allows harvesting of microcrystals of 10 um size or smaller using the Thorne microloops. They can also be safely cryo-protected and hyperquenced using the automated protocols described above. 

Publications, presentations, and videos:

• Poster presented at ACA 2011

• First experiences and usability tests of robot: J. Structural and Functional Genomcis, March 2011 

• The first ever robotically harvested protein crystal yields a high resolution trypsin structure with additive-mediated crystal contacts. J Appl Crystallogr (2007)

• Automated robotic harvesting of protein crystals - addressing a critical bottleneck or instrumentation overkill? Journal of Structural and Functional Genomics (2007)

• Latest presentation given at the 2010 NIH Bottlenecks meeting: Slideshow  PDF

• Movie: Overview of robotic harvesting with the UMR (updated version of production unit soon)

• Movie: New drip-cryoprotection with perfluoroether oil

Contact: