Beamtime at VMXm

Ahead of the beamline session users must complete the session experiment risk assessment (ERA) in the Diamond UAS. The local contact will typically allocate pre-experiment access to the beamline for sample preparation on the day prior to data collection. This will allow users time to prepare samples using the tools in the VMXm sample preparation lab with the help of the local contact. Grids prepared during the pre-experiemnt sample preparation session can be stored at the beamline in a liquid nitrogen storage dewar for the beamline session or subsequent sessions.

• Samples (in crystallisation plates or tubes)
• Additional crystallisation solution

The beamline team will provide all consumables for the sample preparation process including grids, grid storage boxes and blotting paper. Users need only bring with them the samples (tubes or plates) and spare crystallisation solution. The crystallisation solution is required for the blotting process.

The local contact will confirm the session's start time in advance. Users should proceed to the beamline located within Zone 5.

A maximum of 5 sample grids can be loaded into the VMXm sample cartridge for testing at one time.

Data collection typically involves gathering small wedge data from multiple crystals, with the results from these wedges being merged to create a complete dataset. For high-symmetry crystal systems, like cubic, this can be achieved with just a few datasets. However, for lower symmetry systems, such as monoclinic, many more small wedges will need to be merged. This is the primary factor influencing the duration of the beamtime. We generally recommend requesting one shift of beamtime (8 hours) per crystal system. If you're uncertain about how much time to request, please consult the beamline team for guidance.

Data collection can also include screening multiple cryoEM grids containing crystals from various growth conditions. In an 8-hour period, we typically recommend screening around 10 different conditions (equivalent to two sample cartridges).