CombiPuckTM for X-ray crystallography (2017)

Minmin Yu, Adam Fowle, Wai-Ching Hon and Andrew Leslie designed and built a prototype cryopuck (CombiPuckTM) and related tools for the cryogenic storage, transport and robotic handling of mounted crystals used in X-ray diffraction studies to determine molecular structures.

About the CombiPuckTM

Macromolecular crystals grown in the laboratory need to be transported in liquid nitrogen at cryogenic temperatures to synchrotrons for both screening to identify crystals of a suitable quality, and collection of X-ray diffraction data used for structure determination.

Shipping the crystals is generally carried out by commercial carriers and therefore a robust way of storing the crystals in the shipping dewars is required. Once at the synchrotron, the crystals are placed in staging dewars of liquid nitrogen at the beamline and then individually mounted by robots for exposure to X-rays. This also requires a standard and robust way of handling the crystals. Both of these requirements are met by the use of standardised pucks that completely enclose the crystals during shipping, but allow access to the crystals when placed in the robot dewar.

Many laboratories harvest their protein crystals using standard pins that are placed in standard magnetic cryovials in order to protect the crystals. These vials are then placed in canes and stored in liquid nitrogen. Most commercially available pucks do not accommodate these vials and so additional steps are required in order to transfer the crystals from the vials to the pucks, increasing the risk that the crystals (or the crystal mount) will be damaged. CombiPuck™ overcomes this problem as it is able to accommodate the cryovials directly, reducing the risk that the samples will be damaged. In addition, CombiPuck™ makes it much simpler to recover unused samples from the Unipuck base so that they can be stored for later use.

CombiPuck™ has been developed and tested in collaboration with Diamond Light Source in Oxfordshire, the UK’s main synchrotron facility. Andrew Leslie has also worked with Mitegen LLC to further evaluate CombiPuck™ and produce a dependable manufactured product.

CombiPuck™ is protected by registered design rights and the IP has now been exclusively licensed to Mitegen LLC who are currently selling the CombiPuck™ and associated tools.