Compact grid device for fast, automated crystallography

This invention is a simple, versatile, high density grid designed to enable rapid X-ray crystallography by greatly reducing the time spent exchanging and positioning samples. In addition, these grids can be used as scaffolds for growing crystals, eliminating the crystal harvesting step and protecting crystals from human handling. This technology couples highly automated instrumentation (mounting systems and positioning stages) with the specialized grid and customized software for efficient data collection with minimal sample consumption.

In practice, 75 holes embedded in the grid serve as mounting ports for either conventionally-sized crystals or microcrystals samples. These samples can then be stored cryogenically or at room temperature in an SSRL cassette or an uni-puck storage container. The grids enable consistent production of diffraction patterns to collect high redundancy data from either synchrotron or X-ray free-electron laser (XFEL) sources. They can derive high-resolution structures, particularly for very small and delicate crystals that are sensitive to radiation exposure.

Stage of Research
The inventors have used the grid for automated goniometer-based analysis and performed femtosecond crystallography (FX) on a variety of sample types. Their results included a 1.6-A resolution electron density map of rod-shaped Cpl hydrogenase from 125 still diffraction patterns using only 5 crystals and about 30 minutes of beam time. The inventors have also demonstrated their specialized tools and software for the grids for applications including room temperature and cryogenic crystallization experiments that employ commercial liquid-handling robots and incubation chambers which support vapor-diffusion and lipidic cubic phase (LCP) crystallization.