VMXm-Versatile Macromolecular Crystallography microfocus
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David
Regan
,
Ozan
Aksakal
,
John J. K.
Mclarnon
,
Athena
Zitti
,
Magdalena
Lipka-Lloyd
,
Pierre J.
Rizkallah
,
Anna J.
Warren
,
Peter D.
Watson
,
Wolfgang
Langbein
,
D. Dafydd
Jones
,
Paola
Borri
Diamond Proposal Number(s):
[36446]
Open Access
Abstract: Stimulated Raman scattering (SRS) microscopy offers great potential to surpass fluorescent-based approaches, owing to the sharp line width of Raman vibrations amenable to supermultiplex cell imaging, but currently lacks one crucial component: genetically encodable tags equivalent to fluorescent proteins. Here, we show that infrared fluorescent proteins (IRFPs) can be used as genetically encoded SRS probes and benefit from the electronic preresonant SRS enhancement effect with near-infrared exciting pulses, comparable to synthetic dyes reported in the literature. SRS imaging of the nucleus in mammalian cells is demonstrated where a histone protein is fused to an IRFP. This work opens the route toward Raman-based cell imaging using genetically encoded probes, motivating efforts in solving the challenges of photostability and creating a vibrational palette.
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Aug 2026
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I24-Microfocus Macromolecular Crystallography
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Jos J. A. G.
Kamps
,
Philip
Hinchliffe
,
Johan
Glerup
,
Emily I.
Freeman
,
Pauline A.
Lang
,
Catherine
Tooke
,
Michael
Beer
,
Laura
Parkinson
,
Do-Heon
Gu
,
Sehan
Park
,
Nicholas
Devenish
,
Tiankun
Zhou
,
Anastasya
Shilova
,
Samanpreet
Kaur
,
Patrick
Rabe
,
Christopher J.
Schofield
,
James
Spencer
,
Jaehyun
Park
,
Robin L.
Owen
,
Allen M.
Orville
,
Pierre
Aller
Diamond Proposal Number(s):
[25260]
Open Access
Abstract: We describe the design and implementation of a drop-on-fixed-target method for time-resolved serial crystallography at both synchrotron and XFEL facilities. A piezoelectric droplet dispensing pipette is employed for addition of picolitre volume aqueous droplets (∼40–90 pl; ∼40–55 µm diameter sphere), containing (co-)substrate(s) or ligand(s), onto enzyme microcrystals previously loaded into the trapezoidal wells of an etched crystalline silicon fixed-target chip containing 25 600 wells in a high-density, square grid with 125 µm centre-to-centre well spacing. These features demand exquisite accuracy and thereby constrain motion controls to enable robust time-resolved crystallographic studies. The system was tested with three enzyme systems, comprising lysozyme and two β-lactamases, CTX-M-15 and AmpCEC. Mitigation strategies for cross-well contamination, including the implementation of interleaved controls, are described; the overall performance of the system at synchrotron and X-ray free-electron laser facilities was evaluated. This drop-on-fixed-target method is a reliable framework for time-resolved crystallography and will improve the consistency of measurements across facilities.
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Jul 2026
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Krios I-Titan Krios I at Diamond
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Diamond Proposal Number(s):
[21005]
Open Access
Abstract: The dynamic nature of protein and macromolecular complexes means that the capture of multiple sequential states along a reaction pathway can provide much greater insight into function than that obtained from a single static structure. We present a set of modular, easy-to-implement tools and workflows for optical excitation, on-grid characterization and tightly coupled rapid vitrification, establishing a proof-of-principle framework for time-resolved cryoEM and cryo-electron tomography (cryoET). We apply this framework to E. coli chemotaxis, in which serine-sensitive chemoreceptors initiate signalling upon ligand binding and undergo critical conformational changes within the chemosensory arrays. Using DMNB-caged serine [O-(4,5-dimethoxy-2-nitrobenzyl)-L-serine] as a model trigger, we quantified its photophysical properties and uncaging efficiency using UV–Vis spectroscopy and two-dimensional gas chromatography mass spectrometry (GC×GC-MS). Coupling a femtosecond-pulsed laser to a Vitrobot enabled reproducible reaction-to-vitrification delays of ∼150 ms, yielding intact E. coli minicells with well-preserved chemotaxis arrays suitable for in situ structural analysis by cryoET. This integrated approach provides a robust and generalisable framework for millisecond time-resolved cryoET, laying the groundwork for capturing transient conformational states in their native cellular context.
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Jul 2026
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B22-Multimode InfraRed imaging And Microspectroscopy
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Open Access
Abstract: Measuring live cells by FTIR spectroscopy is challenging due to their small size and the absorbance of water in the mid-IR region. However, measuring cells in their live state is important to observe changes in the biological processes of cells that are unaffected by fixation and drying processes. Recently, ZnS hemispheres were used to sandwich live cells in a 6 µm layer of cell medium, which simultaneously limit the absorbance of water and increase the spatial resolution by x2.25, thereby enabling high quality spectra to be acquired from living cells. So far, this method has been used as an imaging technique to showcase the distribution of biomolecules within a single cell. In this work, we present an alternative use of these ZnS hemispheres as a high throughput screening tool. We obtained high quality spectra of a single cell at a measurement rate of ∼1 min/cell. We’ve applied this technique to observe the biochemical effects of various polystyrene microplastics on two mammalian cell lines (J774A.1 and A549), however the method can easily be expanded to other cell lines, microplastics, and alternative xenobiotics.
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Jun 2026
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[39641]
Open Access
Abstract: Steady-state free precession (SSFP) NMR is emerging as a powerful tool across multiple fields of magnetic resonance, driven by its high sensitivity and advances in acquisition and processing. By continuously detecting steady-state transverse magnetization, SSFP achieves superior signal-to-noise ratios per square-root unit time compared to conventional NMR methods that require magnetization recovery between scans. Here, we demonstrate the application of mathematical equation SSFP for fragment-based screening, achieving broadband excitation (mathematical equation kHz) and a 2.6–3.3-fold average sensitivity enhancement relative to broadband Carr–Purcell–Meiboom–Gill approaches. This gain translates into up to a tenfold reduction in experimental time, enabling reliable screening of up to 2000 compounds per day. Together, these features establish mathematical equation SSFP as a robust approach for rapid fragment screening in drug discovery.
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May 2026
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Open Access
Abstract: Serial crystallography relies on the reproducible production of high-density suspensions of microcrystals, yet sample optimization remains a resource-intensive bottleneck. While phase diagrams provide a theoretical framework for controlling crystal size and number, experimental mapping is traditionally hindered by relatively high sample consumption. We present an automated microbatch-under-oil crystallization approach that rapidly maps phase boundaries using only 15–60 µl (∼0.15–3.8 mg) of protein. While this workflow is ideally suited for refining existing hits, it serves as a standalone platform for characterizing the crystallization landscape of new protein targets. The power of this approach lies in the integration of three distinct strategies that exploit the stable chemical environment of microbatch-under-oil. Firstly, we utilize an ingenious diagonal sampling strategy that traverses the phase boundary parallel to the solubility curve by systematically varying protein-to-precipitant ratios, identifying primary nucleation zones with far greater efficiency than traditional orthogonal grids. Secondly, we employ a linked variation of multiple precipitants to reveal morphology-specific regions, such as the rod versus plate transitions crucial for time-resolved experiments. Finally, we incorporate automated seed-stock titration to precisely define the metastable zone, enabling the predictive rescue of nucleation-limited systems. The synergy of these three strategies enables the systematic decoupling of nucleation from growth, providing a rational route to optimize microcrystal density, size and lattice order. Crucially, by eliminating the evaporation-related variables inherent in vapor diffusion, this method ensures that the chemical coordinates identified during screening remain constant during scale-up to larger volumes. This workflow transforms empirical serial crystallography sample preparation into a rational, reproducible and highly efficient process applicable to both the optimization of known conditions and the de novo development of microcrystal suspensions, tailored to the rigorous demands of modern serial diffraction experiments.
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Mar 2026
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I24-Microfocus Macromolecular Crystallography
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Open Access
Abstract: Serial synchrotron crystallography (SSX) enables structure determination from microcrystals under near-physiological, room-temperature conditions but is limited in part due to the inevitable onset of radiation damage. The ability to reduce the absorbed dose while retaining, or even improving, data quality is an attractive means of mitigating this limitation. Advances in detector technology have made the use of high-energy X-rays a routine approach in MX, improving diffraction efficiency and enhancing overall data quality. Here, we systematically evaluate low-dose SSX data collected at five different X-ray energies from 12.4 to 25 keV using a CdTe Eiger2 detector while maintaining a constant dose. Higher photon energies increased the mean diffracted intensity and signal-to-noise ratio per unit dose, and facilitated higher-resolution structure determination, even with limited crystal numbers. These findings highlight the advantages of high-energy X-rays and provide practical guidance for optimizing SSX experiments in probing protein dynamics.
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Mar 2026
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I14-Hard X-ray Nanoprobe
I18-Microfocus Spectroscopy
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Diamond Proposal Number(s):
[39618, 39938, 302085, 31588, 5116, 36811]
Open Access
Abstract: Correlative microscopy linking synchrotron X-ray fluorescence (SXRF) with optical imaging is valuable for contextualizing chemical element distributions in biology. The spatial correlation necessary to achieve this presents fundamental challenges and can be a significant constraint on accuracy and data interpretation. We present a technical solution based on a finder grid concept, optimized for SXRF correlative studies of metals in biological tissues, with scope for wider adaptation and application. A hierarchically patterned fiducial system was directly etched onto spectroscopically clean quartz substrates via femtosecond laser ablation. This design enables improved correlation among SXRF, optical imaging, and histological staining over a greater range of length scales than conventional registration methods such as the use of tissue architecture from serial sections and the use of electron-microscopy-resolution finder grids and applied fiduciary markers that can introduce XRF-signal-dominating levels of elements such as copper, nickel, gold, and titanium. We present two quartz finder grid formats: a microgrid and a nanogrid design. We demonstrate their utility for rapid ROI relocalization and same-section correlative workflows using human brain tissue. The etched quartz finder grid approach facilitates rapid and reproducible ROI relocalization and alignment across instruments, particularly where integral fiducial markers are sparse or ambiguous.
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Mar 2026
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I14-Hard X-ray Nanoprobe
I20-Scanning-X-ray spectroscopy (XAS/XES)
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Diamond Proposal Number(s):
[34837, 38234, 38452]
Open Access
Abstract: Metals play an essential role in cellular homeostasis and are key components of several formulations currently used in the clinic. Synchrotron-based X-ray microscopy at submicron resolution is a powerful approach to map intracellular elemental distributions and to monitor how these patterns change upon genetic or pharmacological perturbations. However, existing sample-preparation protocols often rely on costly and highly specialized equipment for vitrification and dehydration, limiting their widespread adoption. Here, we present an adapted plunge-freezing and freeze-drying workflow that enables the preparation of mammalian cell samples for X-ray fluorescence (XRF) and X-ray absorption spectroscopy (XAS) studies with submicron resolution in a cost-effective and versatile manner. Furthermore, we define acquisition parameters optimized for the reliable detection of low-abundance metals, such as endogenous iron. We anticipate that this accessible protocol will facilitate the broader implementation of synchrotron-based inner-shell spectromicroscopy in cell biology.
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Mar 2026
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[33984]
Open Access
Abstract: In situ tomography enables non-destructive, time-lapse imaging of biological tissues under load, offering insights into structural and mechanical changes. However, repeated scans can expose samples to high radiation doses, potentially altering tissue properties. This study evaluated the feasibility of low-dose synchrotron computed tomography (sCT) for high-resolution, in situ imaging of intact bovine intervertebral discs (IVDs), and assessed the effects of repeated x-ray exposure on mechanical, microstructural, and molecular integrity. Intact oxtail IVD segments were imaged using propagation-based phase contrast sCT at 54 keV. Scan parameters were optimised to achieve high image quality within 66 seconds per scan, resulting in a total absorbed dose of ∼30 kGy over six scans. Mechanical properties were assessed under cyclic loading, microstructural changes via digital volume correlation (DVC), and molecular alterations using Raman spectroscopy. High-resolution imaging of soft and calcified tissues was achieved. Changes in sample stiffness, hysteresis, or stress recovery between irradiated and control were not identified. DVC revealed no microstructural damage or strain accumulation in the calcified endplate. Raman spectroscopy indicated minimal changes in soft tissues, with bone showing slightly increased collagen crosslinking and reduced mineralisation. Overall, this study demonstrates that high-energy, low-dose sCT enables repeated imaging of musculoskeletal tissues without compromising integrity, supporting its application in dynamic, time-lapse imaging studies. Importantly, larger, intact samples, such as whole bovine IVDs, were imaged overcoming limitations of previous studies that relied on small animal models. This approach supports more physiologically relevant investigations of tissue mechanics and degeneration in complex systems.
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Feb 2026
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