Submitting a Sample

Overall Workflow Steps

Contacting

Contact the facility manager, Dr. Ke Shi, by email or filling out a Google form, with crystallization intention. Provide the sequence and sample buffer conditions for analysis using bioinformatics and cheminformatics tools. The facility will select suitable screens and crystallization parameters, but you can also request specific screening strategies, including the choice of crystallization conditions. Available updated screening kits are as follows: Crystal Screen HT, Index, SaltRX, PEG/ION, PEGRx, Membfac (Hampton Research), JCSG+, PACT, ProComplex, Shotgun 1, Shotgun 2, Midas+, Morpheus, Morpheus Fusion, Top96 (Molecular Dimensions)

For protein samples, a preferred protein concentration is 10 mg/ml or higher, but lower concentration samples are acceptable. The sample solution should not contain more than 5 % glycerol. Please also avoid other solvents that increase viscosity. Phosphate-based buffers should be avoided unless it is essential for the stability of the macromolecule of interest. 

Please provide a chart string for the screening fee. Users from the colleges that provide a subsidy benefit from lower rates.

Sample Handover

Schedule an appointment and hand over the sample at the scheduled time, preferably before 1 pm. The facility is located at 1-273, Nils Hasselmo Hall: 312 Church St. S.E., Minneapolis, MN 55455. A volume of 200 microliters is sufficient for setting up 10 plates for 960 conditions. Up to 3 related samples (e.g., same enzyme against 3 different ligands, different variants of an enzyme, etc.) could be screened in parallel against the same set of crystallization conditions if necessary.

Image Inspection

Inspect images on the web server over time (VPN is required for access from outside of the UMN campus). Plates are scanned with JANSi imager periodically under visible light microscopy and UV fluorescence imaging, starting 1 day after the plates are set up. Protein crystals, if the protein has a tryptophan residue, light up in UV fluorescence. The images below show examples of successful protein crystallization.

If crystals are obtained

If you would like to take the screening plates after crystals appear, contact the facility and schedule a plate pick-up.

If you are not sure what to do with the crystals obtained, the facility and the BMBB Aihara lab, in which Dr. Shi is  a senior research associate, can help harvest crystals, collect X-ray diffraction data at synchrotron, and analyze the crystal structure as a collaborative project with your lab (for non-proprietary research).

Alternatively, the facility could test crystals and collect X-ray diffraction data at synchrotron as a fee for service (separate from setting up crystallization screens), which might be a good option if you wish to perform structure analysis yourself but do not have access to X-ray sources.

In any case, if crystals need to be sent to a synchrotron for data collection, please provide the following information in an Excel spreadsheet. Depending on beamtime availability, the lead time can range from one week to 2 months.

If the objects are uncertain to be crystals, they can be inspected through manual inspection, after which they can be sent for X-ray screening.