Anaerobic fixed-target serial crystallography using sandwiched silicon nitride membranes

Abstract

In recent years, the emergence of serial crystallography, initially pioneered at X-ray free-electron lasers (XFELs), has sparked a growing interest in collecting macromolecular crystallographic data at room temperature. Various fixed-target serial crystallography techniques have been developed, ranging from commercially available chips to in-house designs implemented at different synchrotron facilities. Nevertheless, there is currently no commercially available chip (known to the authors) specifically designed for the direct handling of oxygen-sensitive samples. This study presents a methodology employing silicon nitride chips arranged in a `sandwich' configuration, enabling reliable room-temperature data collection from oxygen-sensitive samples. The method involves the utilization of a custom-made 3D-printed assembling tool and a MX sample holder. To validate the effectiveness of the proposed method, deoxyhemoglobin and methemoglobin samples were investigated using the BioMAX X-ray macromolecular crystallography beamline, the Balder X-ray absorption spectroscopy beamline and UV–Vis absorption spectroscopy.

Fixed-Target Pink-Beam Serial Synchrotron Crystallography at Pohang Light Source II

“…However, sample delivery using a viscous material requires not only the selection of a delivery material that can stably store the crystal sample, but also technical efforts to provide a stable injection stream [16]. The fixed-target scanning method is widely applied for SX data collection at XFEL facilities or synchrotrons [19][20][21][22][23][24]. It can minimize sample consumption compared to injection systems and does not physically impact the crystal sample during data collection [25]; in the case of the injector method, pressure is applied to the crystal sample as it passes through the nozzle, which may have a physical effect on the crystal.…”