The TELL automatic sample changer for macromolecular crystallography

In this paper, the design and functionalities of the high-throughput TELL sample exchange system for macromolecular crystallography is presented. TELL was developed at the Paul Scherrer Institute with a focus on speed, storage capacity and reliability to serve the three macromolecular crystallography beamlines of the Swiss Light Source, as well as the SwissMX instrument at SwissFEL.

Automatic sample changer for the analysis of powder samples on an X-ray single-crystal diffractometer equipped with an area detector

A low-budget automatic sample changer that allows the rapid analysis of powder or polycrystalline samples using an X-ray single-crystal diffractometer equipped with an area detector is here described. It uses control software that synchronizes the movement of a linear stage with the collection of frames by the diffractometer. Small pieces of thin solid samples are directly attached to a 30 cm ruler, which is used as a disposable magazine, while loose powder samples are loaded into holes on an acetate strip covered on both sides with Kapton tape and attached to the ruler. The use of this type of diffractometer with a sample changer is a simple, low cost and effective solution for studies requiring the analysis of a large number of samples by X-ray powder diffraction. With the current design up to 30 samples can be measured in a single experiment. The current sample changer was designed so that it can be fitted into a Bruker SMART APEX X-ray single-crystal diffractometer. However, it can be easily adapted to diffractometers from other makers.

Total-scattering-based automatic centring of capillary samples within powder diffractometers

A computer-controlled method for the automatic mechanical centring of a powder capillary sample onto the rotation centre of a powder diffractometer, using total scattering of the radiation beam into one-dimensional or two-dimensional detectors, and only a 90° rotation of the sample stage, is described. This method is particularly useful for situations where powder capillaries are within non-ambient experimental apparatus or loadedviaan automatic sample changer. Irregularly shaped samples, potentially subject to absorption effects, are aligned and centred on the sample's `scattering centre'.