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Sample-exchange robots with a double-tongs system that could exchange samples within 10 s have been developed., Sample-exchange robots that can exchange cryo-pins bearing protein crystals out of experimental hutches according to user instructions have been developed. The robots were designed based on the SAM (Stanford Synchrotron Research Laboratory automated mounting) system. In order to reduce the time required for the sample exchange, the single tongs of the SAM system were modified and a double-tongs system that can hold two cryo-pins at the same time was developed. Robots with double tongs can move to the goniometer head holding the next cryo-pin with one set of tongs, dismount the experimented cryo-pin with the other set, and then mount the next pin onto the goniometer head without leaving the diffractometer area. Two different types of tongs have been installed: single tongs at beamlines BL-5A and AR-NW12A, and a double-tongs system at beamline BL-17A of the Photon Factory. The same graphical user interface software for operation of the sample-exchange robots is used at all beamlines, however, so that users do not need to consider differences between the systems. In a trial, the robot with double tongs could exchange samples within 10 s.

We are now developing automated sample exchange robots for high‐throughput protein crystallographic experiments for onsite use at synchrotron beam lines. It is part of the fully automated robotics systems being developed at the Photon Factory, for the purposes of protein crystallization, monitoring crystal growth, harvesting and freezing crystals, mounting the crystals inside a hutch and for data collection. We have already installed the sample exchange robots based on the SSRL automated mounting system at our insertion device beam lines BL‐5A and AR‐NW12A at the Photon Factory. In order to reduce the time required for sample exchange further, a prototype of a double‐tonged system was developed. As a result of preliminary experiments with double‐tonged robots, the sample exchange time was successfully reduced from 70 seconds to 10 seconds with the exception of the time required for pre‐cooling and warming up the tongs.

An integrated client‐server control system (PCCS) with a unified relational database (PCDB) has been developed for high‐throughput protein crystallography experiments on synchrotron beamlines. The major steps in protein crystallographic experiments (purification, crystallization, crystal harvesting, data collection, and data processing) are integrated into the software. All information necessary for performing protein crystallography experiments is stored in the PCDB database (except raw X‐ray diffraction data, which is stored in the Network File Server). To allow all members of a protein crystallography group to participate in experiments, the system was developed as a multi‐user system with secure network access based on TCP/IP secure UNIX sockets. Secure remote access to the system is possible from any operating system with X‐terminal and SSH/X11 (Secure Shell with graphical user interface) support. Currently, the system covers the high‐throughput X‐ray data collection stages and is being commissioned at BL5A and NW12A (PF, PF‐AR, KEK, Tsukuba, Japan).

A 3 x 6 arrayed charge-coupled device (CCD) X-ray detector has been developed for the continuous-rotation method in macromolecular crystallography at the Photon Factory. The detector has an area of 235.9 mm x 235.9 mm and a readout time of 1.9 s. The detector is made of a 3 x 6 array of identical modules, each module consisting of a fiber-optic taper (FOT), a CCD sensor and a readout circuit. The outputs from 18 CCDs are read out in parallel and are then digitized by 16-bit analog-to-digital converters. The advantage of this detector over conventional FOT-coupled CCD detectors is the unique CCD readout scheme (frame transfer) which enables successive X-ray exposures to be recorded without interruption of the sample crystal rotation. A full data set of a lysozyme crystal was continuously collected within 360 s (180 degrees rotation, 3 s/1.5 degrees frame). The duty-cycle ratio of the X-ray exposure to the data collection time was almost 100%. The combination of this detector and synchrotron radiation is well suited to rapid and continuous data collection in macromolecular crystallography.

A 3 × 6 arrayed charge coupled device (CCD) X‐ray detector has been developed for rapid data collection in macromolecular crystallography at Photon Factory. The total active area is 236 mm × 236 mm (76.8 μm × 76.8 μm / pixel at the input phosphor, 3072 × 3072 pixels). Each module consists of an input phosphor, a 3.2 : 1 fiber‐ optic‐taper (FOT), a CCD, and a readout circuit. The input phosphor is Gd2O2S:Tb (P‐43), which is deposited onto an aluminum coated Mylar sheet to increase the sensitivity. The outputs from eighteen (3 × 6) CCDs are readout in parallel and then are digitized by 16 bit analog‐to‐digital converters. The advantage of this detector over the conventional FOT‐coupled CCD detectors is a unique CCD readout scheme that enables us to record successive x‐ray exposures without interruption among them. A shutter is not needed for CCD readout and the sample crystal can be rotated continuously without interruption during data acquisition. We have collected one data set of a Lysozyme crystal for 180 degree with 1.5 degree per slice in 360 seconds. The exposure time of each slice is 3 seconds. The duty‐ratio of the x‐ray exposure to the data collection time is 100 %. This detector combined with a synchrotron radiation source is very suitable for rapid data collection in macromolecular crystallography.

A control system for high-throughput protein crystallography experiments has been developed based on a multilevel secure (SSL v2/v3) UNIX socket under the Linux operating system. Main features of protein crystallography experiments (purification, crystallization, loop preparation, data collecting, data processing) are dealt with by the software. All information necessary to perform protein crystallography experiments is stored (except raw X-ray data, that are stored in Network File Server) in a relational database (MySQL). The system consists of several servers and clients. TCP/IP secure UNIX sockets with four predefined behaviors [(a) listening to a request followed by a reply, (b) sending a request and waiting for a reply, (c) listening to a broadcast message, and (d) sending a broadcast message] support communications between all servers and clients allowing one to control experiments, view data, edit experimental conditions and perform data processing remotely. The usage of the interface software is well suited for developing well organized control software with a hierarchical structure of different software units (Gaponov et al., 1998), which will pass and receive different types of information. All communication is divided into two parts: low and top levels. Large and complicated control tasks are split into several smaller ones, which can be processed by control clients independently. For communicating with experimental equipment (beamline optical elements, robots, and specialized experimental equipment etc.), the STARS server, developed at the Photon Factory, is used (Kosuge et al., 2002). The STARS server allows any application with an open socket to be connected with any other clients that control experimental equipment. Majority of the source code is written in C/C++. GUI modules of the system were built mainly using Glade user interface builder for GTK+ and Gnome under Red Hat Linux 7.1 operating system.