Robots Enhance Protein Crystallography Throughput at Stanford Synchrotron Radiation Laboratory (SSRL)
An experimental run in October 2002 with manual handling of the crystals required 24 hours to screen 100 crystals of a protein complex, with several crystals being damaged or lost. A run by the same group two weeks later, but this time using the new SSRL robotic system, saw 130 crystals screened in less than eight hours, with no crystal being damaged or lost. Clearly the coming widespread implementation of robotics at crystallography beamlines will enable a substantial increase in the number of users that can be accommodated. The process of obtaining the x-ray crystallographic data needed for solving the three dimensional structure of a protein or other biological macromolecule involves screening of numerous crystals of a molecule to find the ones that give the best resolution. Until recently this required manual handling of each of 100 or more crystals, with the researchers having in the process to carry out a multi-step protocol to shut off the x-ray beam into the experimental hutch, gain access to the diffractometer station in the hutch, change the crystal, leave the hutch, and open the beam shutter. All of the Department of Energy synchrotron light sources are implementing automated systems for carrying out these steps. The recent experience of a prominent structural biology research group at SSRL illustrates the benefits these systems will bring.