Experiences with the Rigaku/MSC ACTOR robotic system at IMCA-CAT

Anne Mulichak
IMCA-CAT, Advanced Photon Source, Argonne National Laboratory

The Industrial Macromolecular Crystallography Association Collaborative Access Team (IMCA-CAT) operates a data collection facility for macromolecular crystallography located at Sector 17 of the Advanced Photon Source. This facility satisfies the demands of the IMCA member pharmaceutical companies to perform experiments in high-throughput mode for drug discovery and product development. A Rigaku/MSC ACTOR robot installed at the 17-ID beam line provides automated mounting, centering, and retrieval of protein samples. The 6-axis industrial robot uses a 4-finger arm for sample transfer and can accommodate many experimental configurations. In fully automatic mode, the storage dewar capacity of 60 samples can be screened in approximately 3 hours, with drying and re-cooling of the robot arm between sample exchanges being the rate-limiting step. Auto-centering, based on loop recognition and employing a two camera system for sample visualization, is rapid and robust under a variety of lighting conditions. The robot is operated using JDirector software in a tabbed notebook format, integrated with data collection and some beam line controls. Varying levels of automation are available, from completely automated sample screening and unattended data acquisition according to user-programmed schedules, to semi-automatic or fully manual modes. The ACTOR can be additionally used for auxiliary functions, such as annealing mounted samples. Pin detection monitoring, which allows the robot to detect and respond to errors in sample transfer, as well as automated email page alerts of robot errors, provide operators with additional assurance of robot performance. Now a reliable and integral component of the 17-ID beam line, the ACTOR robot is used routinely by IMCA researchers and is available to general users. Users report at least a two-fold increase in the number of crystals screened and data sets collected, while at the same time sending fewer scientists and often finishing experiments before the end of their scheduled beamtime. Based on the success of robotics at IMCA-CAT, the purchase of a second ACTOR system is planned.