UCLA researchers have developed a suspended drop crystallization device and associated methods that allow a sample to be applied directly onto a support-free electron microscopy grid and then incubated in a chamber (“incubation pod”) that permits vapor diffusion from both sides. The device has viewing windows for monitoring crystal growth, and once crystals form, the grid can be removed for imaging or crystallography without intermediate handling or support films.
In traditional crystallography and electron microscopy workflows, sample preparation often involves support films, blotting, transfers, or other handling steps that can damage fragile crystals, distort their orientation, or reduce resolution. The need to transfer samples or use supports can also introduce artifacts. Additionally, limited access to monitoring during crystal growth hinders optimization. There is a need for a device that simplifies preparation, preserves orientation, minimizes handling, and allows real-time monitoring of crystallization directly on the imaging substrate.
This technology employs an apparatus where a sample is pipetted directly onto a support-free EM grid (i.e. no additional film support). The grid is then suspended inside an incubation pod, which has windows allowing observation of the sample drop from both sides as vapor diffusion proceeds. Because diffusion is allowed from both sides of the suspended drop, the growth environment can be more uniform. After sufficient crystal growth, the grid can be removed and used for crystallography data acquisition. The device reduces or eliminates steps like blotting or sample transfer, thereby preserving crystal integrity and orientation.
Reduced sample handling: fewer transfer or support-film steps, lowering damage risk.
Preservation of crystal orientation and morphology, since samples are grown directly on the imaging grid.
Ability to monitor growth in situ through windows from both sides of the suspended drop.
Avoids blotting (a common step that can distort samples or cause losses).
Support-free grid avoids background from support layers, potentially improving imaging clarity.
Simplifies workflow, which could improve throughput and success rates for crystallography or EM studies.
Protein crystallography, especially for delicate or small crystals, where handling damage is a concern.
Cryo-electron microscopy sample preparation, where support films or blotting steps are commonly used.
Structural biology labs seeking to streamline workflow and improve resolution / orientation control.
High-throughput screening of crystallization conditions with reduced sample loss.
Imaging of molecular assemblies or macromolecules where preserving native orientation matters (e.g. cryo-EM, electron diffraction).
WO2024/130038 A1 — Suspended Sample Growth Device for Imaging Applications Priority Date: December 14, 2022; International Filing: December 14, 2023; Publication: June 20, 2024. Suspended Sample Growth Device for Imaging Applications (WO2024130038A1) Google Patents+1