Structural Genomics Consortium, University of Oxford, ORCRB, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom.
I04-1, Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0QX, United Kingdom.
Acta Crystallogr D Struct Biol. 2021 Jan 1;77(Pt 1):62-74. doi: 10.1107/S2059798320014114.
Despite the tremendous success of X-ray cryo-crystallography in recent decades, the transfer of crystals from the drops in which they are grown to diffractometer sample mounts remains a manual process in almost all laboratories. Here, the Shifter, a motorized, interactive microscope stage that transforms the entire crystal-mounting workflow from a rate-limiting manual activity to a controllable, high-throughput semi-automated process, is described. By combining the visual acuity and fine motor skills of humans with targeted hardware and software automation, it was possible to transform the speed and robustness of crystal mounting. Control software, triggered by the operator, manoeuvres crystallization plates beneath a clear protective cover, allowing the complete removal of film seals and thereby eliminating the tedium of repetitive seal cutting. The software, either upon request or working from an imported list, controls motors to position crystal drops under a hole in the cover for human mounting at a microscope. The software automatically captures experimental annotations for uploading to the user's data repository, removing the need for manual documentation. The Shifter facilitates mounting rates of 100-240 crystals per hour in a more controlled process than manual mounting, which greatly extends the lifetime of the drops and thus allows a dramatic increase in the number of crystals retrievable from any given drop without loss of X-ray diffraction quality. In 2015, the first in a series of three Shifter devices was deployed as part of the XChem fragment-screening facility at Diamond Light Source, where they have since facilitated the mounting of over 120 000 crystals. The Shifter was engineered to have a simple design, providing a device that could be readily commercialized and widely adopted owing to its low cost. The versatile hardware design allows use beyond fragment screening and protein crystallography.
尽管 X 射线晶体学在最近几十年取得了巨大的成功，但将晶体从它们生长的液滴转移到衍射仪样品架仍然是几乎所有实验室中的一个手动过程。在这里，描述了 Shifter，这是一种电动、交互式显微镜载物台，它将整个晶体安装工作流程从一个限制速度的手动活动转变为可控制的、高通量的半自动过程。通过将人类的视觉敏锐度和精细运动技能与目标硬件和软件自动化相结合，有可能提高晶体安装的速度和稳健性。操作人员触发的控制软件操纵结晶板在透明保护盖下移动，从而完全去除薄膜密封件，从而消除了重复切割密封件的繁琐。该软件可根据请求或从导入列表中控制电机，将晶体液滴定位在盖下的孔下，以便在显微镜下进行人工安装。该软件自动捕获实验注释，以便上传到用户的数据存储库，从而无需手动记录。Shifter 以比手动安装更受控的过程实现了 100-240 个晶体/小时的安装速度，大大延长了液滴的寿命，从而允许从任何给定液滴中检索更多数量的晶体，而不会损失 X 射线衍射质量。2015 年，作为 Diamond Light Source 的 XChem 片段筛选设施的一部分，部署了第一批 Shifter 设备中的一个，自那时以来，它们已经协助安装了超过 120000 个晶体。Shifter 的设计简单，成本低，易于商业化和广泛采用。多功能硬件设计允许超越片段筛选和蛋白质晶体学的应用。
